Water Reclamation Facility - Facility Plan
Executive Summary
FINAL / February 2024
1401 FULTON STREET, SUITE 802 ▪ FRESNO, CALIFORNIA 93721 ▪ P 559-436-6616
Water Reclamation Facility - Facility Plan
Executive Summary
FINAL / February 2024
This document is released for the purpose of information exchange review and planning only under the authority of Kyle T. Leonard, February 2024, CA PE 86011.
EXECUTIVE SUMMARY
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN i
Contents
EXECUTIVE SUMMARY ES-1
ES.1 Introduction ES-1
ES.2 Background and Purpose ES-1
ES.3 Technical Memorandum 1 – Near-Term Process Performance Evaluation ES-1 ES.4 Technical Memorandum 2 – Condition Assessment ES-2 ES.4.1 Preliminary Treatment ES-2
ES.4.2 Primary Treatment ES-2
ES.4.3 Secondary Treatment ES-3
ES.4.4 Tertiary Treatment ES-3
ES.4.5 Solids Handling ES-3
ES.5 Technical Memorandum 3 – Environmental Opportunities ES-3 ES.5.1 Class A Biosolids Opportunities ES-3
ES.5.2 Energy Opportunities ES-4
ES.6 Technical Memorandum 4 – Near-Term Project Descriptions ES-5 ES.6.1 Thickened Waste Activated Sludge Pump Replacements ES-5 ES.6.2 Dewatering Capacity Expansion ES-5
ES.6.3 Anaerobic Digestion Capacity Expansion ES-5
ES.6.4 Ultraviolet (UV) Disinfection System Capacity Expansion ES-6 ES.7 Technical Memorandum 5 – Near-Term Capital Improvement Program ES-6 ES.7.1 Cost Estimate ES-6
ES.7.2 Project Implementation ES-6
ES.8 Technical Memorandum 6 – Near-Term Capital Improvement Program Financing Opportunities ES-7
ES.9 Summary and Recommendations ES-7
Tables
Table ES.1 Class A Treatment Options, High-Level Cost Estimates, Recommendations ES-4 Table ES.2 Total Project Capital Cost for Recommended Project ES-6 Figures
Figure ES.1 Near-Term Projects CIP Schedule ES-7
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WATER RECLAMATION FACILITY - FACILITY PLAN ii
Abbreviations
AADF average annual daily flow
BOD biochemical oxygen demand
City City of Visalia
CIP capital improvement program
HRT hydraulic retention time
KOH potassium hydroxide
MCC motor control center
MBR membrane bioreactor
mgd million gallons per day
NaOH sodium hydroxide
PS primary sludge
PWWF peak wet weather flow
RAS return activated sludge
THP thermal hydrolysis process
TM technical memorandum
TPAD temperature phased anaerobic digestion
TS total solids
TSS total suspended solids
TWAS thickened waste activated sludge
UV ultraviolet
VFD variable frequency drive
WRF Water Reclamation Facility
EXECUTIVE SUMMARY
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WATER RECLAMATION FACILITY - FACILITY PLAN ES-1
EXECUTIVE SUMMARY
ES.1 Introduction
The Facility Plan is the first step in evaluating the current capacity of the City of Visalia’s (City) Water Reclamation Facility (WRF), using a biological process model. This will set the basis for developing the framework for improvements required to meet the WRF’s near-term (6-year) needs. The biological process model was calibrated to the existing and current flow/loadings data, and then used to determine capacity deficiencies based on the projected future flows/loads, which were developed using annual growth projections. Capacity expansion projects were developed for the identified treatment processes with capacity deficiencies. A near-term capacity improvement program was developed as well.
ES.2 Background and Purpose
The City’s WRF treats domestic and industrial wastewater from the City, as well as wastewater from the Goshen Community Services District. Due to the Central Valley Water Boards’s adoption of the updated National Pollutant Discharge Elimination System, which increased regulation on processed wastewater discharge into Mill Creek, major upgrades were implemented to divert discharge from Mill Creek. These upgrades, which were constructed in 2017, included membrane bioreactor (MBR) treatment facilities, a new digester, sludge handling facilities, and disinfection facilities to support continued discharge to the Tulare Irrigation District for agricultural uses, along with reuse at the golf course. Th is project made various improvements resulting in the ability to produce Title 22 compliant recycled water . It was not intended to increase plant capacity, but rather to provide process equipment to support the more stringent wastewater effluent quality requirements. Improvements made to the treatment system were designed around an average annual daily flow (AADF) of 22 mgd; however, to save overall costs, some of the equipment was sized to handle an AADF of 18 mgd.
In recent years, industrial loads have significantly increased, as well as an increase in water conservation efforts in residential wastewater within the City and Goshen, has caused increased influent concentrations.
These increased influent concentrations have had a direct impact on the WRF, which is operating near its maximum capacity when it comes to influent biochemical oxygen demand (BOD) and total suspended solids (TSS). These elevated loading concentrations are putting excessive stress on some of the treatment processes and leading to disruptions and disturbances.
The Facility Plan is the first step to evaluate the current capacity of the WRF as well as the condition of the assets to develop the framework for improvements required to meet the WRF’s near-term needs.
ES.3 Technical Memorandum 1 – Near-Term Process Performance Evaluation
This technical memorandum (TM) provides an overview of the WRF, the historical and projected influent flows and loads, and the performance and capacity assessments. These performance and capacity assessments were used to identify near-term capacity improvement projects to serve as the basis for the near-term capital improvement plan.
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The existing performance of the treatment processes at the WRF was evaluated by comparing the effluent limits to data from January 2018 to April 2023. Overall, the WRF has performed adequately, and plant staff have maintained the facilities in order to meet the effluent limits.
In order to determine the WRF’s current total capacity, a process model was used to determine the flow and loading on each treatment process using data from the plant. The model was then used to compare real-life impacts to the treatment process, and capacity ratings were used to determine if the plant could meet the projected 2030 flows.
The results of the analysis indicated that the current WRF has a total capacity of 13.9 mgd (which is less than the 18 mgd design based on the current plant loadings), and the plant’s current average annual flows are around 12.6 mgd. However, it was determined that plant’s firm capacity, the capacity with the largest unit out of service, is less than the current influent flows. The plant’s firm capacity is currently limited by the dewatering process that has an equivalent AADF firm capacity of 7.1 mgd. Two other unit processes that have firm capacities below the current influent flows are anaerobic digestion and ultraviolet disinfection system. Because of this, four projects were recommended to address these capacity issues, which are discussed in TM 4 – Near-Term Project Descriptions.
ES.4 Technical Memorandum 2 – Condition Assessment
This TM summarizes findings for mechanical, structural, and electrical observations for assets in the preliminary, primary, secondary, and tertiary treatment areas as well as the solids handling area of the WRF. The conclusions and recommendations can be seen below for the different areas.
ES.4.1 Preliminary Treatment
The mechanical, structural, and electrical equipment and structures are generally in good to acceptable condition. Some improvements need to be made in this area though. Notable recommended improvements include the following:
▪ Coat and paint corroded equipment.
▪ Seal the influent gates to improve the leaking in the hydraulic system. ▪ Replace the biofilter media since it is approaching its 10-year lifespan. ▪ Improve the South Diversion Structure.
▪ Repair the cracking at the Septage Receiving Station. ▪ Consider replacing MCC-H to avoid possibly lengthy downtime in the future due to difficulty in finding replacement parts.
▪ Consider replacing the VFD cabinets that have not been replaced. ▪ Conduct an arc flash study since the last one was performed about five years ago.
ES.4.2 Primary Treatment
Similar to the preliminary treatment area, most of the mechanical, structural, and electrical equipment and structures are in good to acceptable condition. However, piping in Scum Box No. 1 was deemed to be in poor condition. Notable recommended improvements to this area are as follows:
▪ Coat and paint corroded equipment.
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▪ Replace the piping in Scum Box No. 1.
▪ Conduct an arc flash study since the last one was performed about five years ago.
ES.4.3 Secondary Treatment
This area is also in good to acceptable condition for all disciplines. Recommended improvements are as follows:
▪ Install piping from the air release valves to the drains to avoid spillage on the equipment and piping. ▪ Coat and paint the return activated sludge (RAS) pumps and the hand cranks on the gates in the junction and flow distribution boxes due to spillage and corrosion, respectively. ▪ Periodically inspect the corrosion at the brace and gusset connection near the MBR system to monitor this development.
▪ Consider relocating the MCCs that are still in use and fully decommissioning those that are mostly decommissioned.
ES.4.4 Tertiary Treatment
This area was mainly included in the last major project, which was constructed in 2017. The mechanical, structural, and electrical assessments observed that this area is in good condition. No recommended improvements are needed here.
ES.4.5 Solids Handling
Both structurally and electrically, this area is in good condition. Mechanically it is in generally in acceptable condition. The following improvements are recommended:
▪ Coat and paint corroded equipment.
▪ Install a third screw press in the near future to provide critical redundancy to the WRF. ▪ Address the poor drainage under the screw presses.
ES.5 Technical Memorandum 3 – Environmental Opportunities This TM presents the findings of the evaluation of environmental opportunities performed for the City’s WRF. The evaluation includes potential environmental project options to include in the Near -Term and Long-Term capital improvement programs (CIPs) for class A biosolids opportunities and energy opportunities.
ES.5.1 Class A Biosolids Opportunities
This investigation includes understanding regulatory and financial drivers and evaluating different treatment technologies to achieve Class A biosolids. Table ES.1 presents different technologies that were evaluated, a high-level cost estimate, and whether the technology was recommended for further investigation or not.
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Table ES.1 Class A Treatment Options, High-Level Cost Estimates, Recommendations Class A
Technology General Description Capital Cost
Estimate (1) Recommendation
Thermal Hydrolysis
Process (THP)
Pre-digestion thermal hydrolysis uses high heat and high pressure to stabilize sludge prior to anaerobic digestion.
$23 Million Further evaluation
recommended
Batch Temperature
Phased Anaerobic
Digestion (TPAD)
Batch TPAD involves a thermophilic continuous phase,
followed by a bath thermophilic phase, and a mesophilic continuous phase.
Highly
variable. $10
to $40 Million
depending on
modifications
required.
Further evaluation
recommended
Thermo-Chemical
Hydrolysis Process
Post-digestion thermo-chemical hydrolysis uses low heat, and high Ph through addition of KOH/NaOH and high shear mixing.
$22 Million Not recommended
Thermal Drying
Thermal drying typically uses a fuel such as natural gas or digester gas to dry dewatered solids. Various technology options including belt, rotary drum, and paddle dryers. $64 Million Not recommended
Thermal Drying
with Pyrolysis/
Gasification
Dried solids are processed in either a zero-oxygen
environment (pyrolysis) or an oxygen-starved environment (gasification). Both processes produce biochar.
$104 Million Not recommended
Composting
Biosolids and bulking agents (agricultural, yard, or wood waste) are ground, combined into piles for composting and curing, and then screened. Various technology options
including windrow, aerated static pile, and in-vessel
composting.
$16 Million Further evaluation
recommended
Notes:
(1) Cost estimates were roughly estimated based on Carollo’s biosolids master planning and digestion upgrades estimating experience.
After completing this analysis, it is recommended to consider a biosolids master plan to comprehensively evaluate options for solids treatment and biosolids product management.
ES.5.2 Energy Opportunities
This investigation also includes understanding regulatory and financial drivers and evaluating different digester gas utilization and energy generation alternatives. Alternatives for digester gas utilization include uses for digester heating, cogeneration or combined heat and power systems (CHP), upgrading it to renewable natural gas (RNG) for pipeline injection, and upgrading and compressing digester gas to produce renewable compressed natural gas (R-CNG).
Since the City’s WRF already has a digester gas conditioning and cogeneration system, it is recommended to resolve the permitting issue to utilize the existing equipment, making this the least costly option.
Additionally, the City is currently purchasing natural gas to run the boilers because they are not currently permitted to operate them using digester gas, resulting in 100 percent of the digester gas being flared.
Resolving this permitting issue should be the first priority. If these permitting issues c annot be resolved,
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the City should consider either performing a digester gas use study or a more comprehensive energy master plan.
ES.6 Technical Memorandum 4 – Near-Term Project Descriptions This TM summarizes projects that are recommended for implementation within the next six years based on the capacity analysis summarized in TM 1 – Near-Term Process Performance Evaluation.
ES.6.1 Thickened Waste Activated Sludge Pump Replacements Currently, thickened waste activated sludge (TWAS) is not thickened to its fullest potential of 5 percent total solids (TS) due to the TWAS pumps tripping from too high of pressure. Therefore, the sludge is thickened to 2.5 percent TS, resulting in a significantly higher amount of sludge being sent to the plant’s digesters. This reduces the overall digestion capacity since it is currently limited by the hydraulic retention time (HRT) and not the solids loading rate.
It is recommended to implement the TWAS Pump Replacements project as soon as possible to restore some digestion capacity. Therefore, the project should be on an expedited design and construction schedule.
ES.6.2 Dewatering Capacity Expansion
Currently, the City’s WRF has two existing screw presses that were designed to operate as one duty and one standby unit. Currently, the dewatering system does not have sufficient firm capacity for the current flows and loads. Therefore, when flows and loads are high, the plant must operate both screw presses to dewater all of the sludge. Operating both units does not allow plant staff to take a unit out of service, so additional dewatering capacity is required to provide critical redundancy to improve opera tions of the dewatering process.
It is recommended to add a third screw press with the same capacity as the existing screw presses and implement the project as soon as possible to provide redundancy for the dewatering system. Like the TWAS pump replacements, this project should also be on an expedited design and construction schedule.
ES.6.3 Anaerobic Digestion Capacity Expansion
As previously stated, the capacity of the anaerobic digestion system is currently limited by the HRT criteria. At current sludge flows, the digestion system is below capacity with the largest digester, Digester No. 8, out of service, so another digester is needed now to allow the largest digester to be taken out of service. However, it is estimated to take at a minimum 3 years to design, construct, and have a new digester be placed into service. Therefore, thickening the primary sludge (PS) and TWAS f eed to the digesters is critical for delaying the need of a new digester by a few years to allow for time to implement the Anaerobic Digestion Capacity Expansion project.
It is recommended to add a new digester with the same digestion and sludge storage capacities as Digester No. 8. This new digester would allow the plant to meet the required HRT for Class B biosolids if Digester No. 8 needs to be taken offline and provide necessary redundancy to the digestion system.
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ES.6.4 Ultraviolet (UV) Disinfection System Capacity Expansion The UV system’s peak flow firm capacity, 28.8 mgd, is insufficient to meet the projected 2030 peak wet weather flows (PWWF), 30.2 mgd. In order to have sufficient firm capacity and redundancy for the projected 2030 PWWFs, the UV system must be expanded and brought online by 2027. Four additional UV modules and associated equipment should be installed to meet future capacity needs. Provisional space was included in the 2017 project in the existing UV channels and for the electrical equipment to allow for this expansion.
ES.7 Technical Memorandum 5 – Near-Term Capital Improvement Program
The near-term capital improvement program (CIP) identifies critical near-term capacity related projects, which are described in TM 4 – Near-Term Project Descriptions, required at the WRF over the next six years. Cost estimates were conducted for the projects, and a schedule of the projects was developed as well.
ES.7.1 Cost Estimate
Total project cost estimates for each project are summarized in Table ES.2. The estimate is at a planning level and is limited to capital costs and does not include O&M costs.
Table ES.2 Total Project Capital Cost for Recommended Project Project Cost (1)
TWAS Pump Replacements $675,000
Dewatering Capacity Expansion $5,313,000
Anaerobic Digestion Capacity Expansion $42,938,000
UV Disinfection System Capacity Expansion $1,488,000
Notes:
(1) Total project capital costs are provided as present value based on an ENR CCI number of 15157 corresponding to the 20 - City Average Index in September 2023. Costs are escalated to the midpoint of construction with an annual inflation rate of 6 percent. Total project costs include factors for estimating contingency, sales tax, general conditions, and contractor overhead and profit as well as 25 percent allowance for engineering, legal, administration, and permitting costs.
ES.7.2 Project Implementation
The implementation timing, determined by when the plant needs additional capacity, and the project duration assign each project a start and completion date. An expedited schedule for design and construction was used for the TWAS pump replacement and dewatering capacity expansion projects. The recommended implementation schedule for the near-term projects can be seen in Table ES.2.
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WATER RECLAMATION FACILITY - FACILITY PLAN ES-7
Figure ES.1 Near-Term Projects CIP Schedule
ES.8 Technical Memorandum 6 – Near-Term Capital Improvement Program Financing Opportunities
This TM summarizes current federal and state grants and low-interest loans that are potential sources of financing for the City’s WRF near-term projects. These programs are competitive and limited in their funding capacity, with program funding availability dependent upon annual appropriations, along with other restrictions.
The following funding opportunities may provide for low interest loan or grant opportunities for the projects listed in the City’s Near-Term CIP:
▪ U. S. Environmental Protection Agency – Water Infrastructure Finance Innovation Act (low interest financing).
▪ Department of Energy – Energy Efficiency and Conservation Block Grant Program (grant or voucher program).
▪ State of California – Community Project Funding / Congressionally Directed Spending (directed appropriations via Congress).
▪ State of California – Infrastructure State Revolving Fund (loan program). ▪ State of California – Clean Water State Revolving Fund (low interest financing with eligible principal forgiveness for disadvantaged communities and green projects).
ES.9 Summary and Recommendations
This Facility Plan outlines key near-term project recommendations and identifies improvements for the WRF. As described above, it is recommended to complete the following projects within the next six years to maintain adequate firm capacity, allowing for necessary redundancy:
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WATER RECLAMATION FACILITY - FACILITY PLAN ES-8
▪ TWAS pump replacements (emergency project): Replace the TWAS pumps, so sludge can be thickened to its fullest potential. It is critical to implement this project as soon as possible to restore some capacity to the digesters, allowing for time to complete the digester expansion project. This project should be on an expedited design and construction schedule. ▪ Dewatering capacity expansion (emergency project): Install a third screw press with the same capacity as the existing screw presses to provide critical redundancy. This project should also implement the project as soon as possible. Like the TWAS pump replacements, this project should also be on an expedited design and construction schedule.
▪ Anaerobic digestion capacity expansion (5-year completion): Add a new digester with the same digestion and sludge storage capacities as Digester No. 8. This will increase the digestion capacity and allow the plant to meet the required HRT for Class B biosolids if Digester No. 8 needs to be taken offline as well as provide necessary redundancy to the digestion system. ▪ UV disinfection system capacity expansion (5-year completion): Install additional UV modules and associated electrical equipment to provide imperative firm capacity to the UV system. This will also provide necessary redundancy.
Overall, the WRF is in good condition. Some improvements need to be made to address some defects observed at the WRF. These improvements are as follows:
▪ Coat and paint corroded equipment and piping.
▪ Conduct an arc flash study since the last one was performed about five years ago. ▪ Conduct structural inspections in 10 years.
▪ Seal the influent gates to improve the leaking in the hydraulic system. ▪ Replace the biofilter media since it is approaching its 10-year lifespan. ▪ Improve the South Diversion Structure.
▪ Repair the cracking at the Septage Receiving Station. ▪ Replace the piping in Scum Box No. 1.
▪ Install piping from the air release valves to the drains to avoid spillage on the equipment and piping. ▪ Periodically inspect the corrosion at the brace and gusset connection near the MBR system to monitor this development.
▪ Address the poor drainage under the screw presses.
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 1
Near-Term Process Performance
Evaluation
FINAL / February 2024
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 1
Near-Term Process Performance
Evaluation
FINAL / February 2024
This document is released for the purpose of information exchange review and planning only under the authority of Andre Gharagozian, February 2024, CA PE 60968.
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN i
Contents
TM 1 NEAR-TERM PROCESS PERFORMANCE EVALUATION 1-1
1.1 Introduction 1-1
1.2 Description of Existing Facilities 1-1
1.3 Historical Influent Flows and Loads 1-2
1.4 Flow and Load Projections 1-4
1.5 Existing Treatment Process Performance 1-7
1.6 Biological Model 1-13
1.6.1 Summary of Model Calibration Results 1-13
1.6.2 Solids Mass Balance 1-14
1.7 Capacity Analysis 1-15
1.7.1 Capacity Analysis Summary 1-15
1.7.2 UV Disinfection System 1-18
1.7.3 Anaerobic Digestion System 1-18
1.7.4 Dewatering System 1-20
Appendices
APPENDIX A FLOW AND LOAD DATA
APPENDIX C BIOLOGICAL MODEL INFORMATION
APPENDIX D ANAEROBIC DIGESTER PERFORMANCE
Tables
Table 1 Historical Flows and Loads 1-3
Table 2 Historical Peaking Factors 1-4
Table 3 Flow and Load Projections Summary 1-5
Table 4 Effluent Limits and Average Performance 1-8
Table 5 Unit Process Performance and Capacity Criteria 1-9 Table 6 Unit Process Capacities 1-16
Figures
Figure 1 Historical Daily Raw Influent Flow Data 1-2
Figure 2 Historical Daily Raw Load Data for BOD (Top) and TSS (Bottom) 1-3 Figure 3 Influent Flow Projections For 2023 To 2030 1-6 Figure 4 BOD And TSS Load Projections For 2023 To 2030 1-7 Figure 5 BioWin Configuration for WRF 1-13
Figure 6 Unit Process Capacities 1-15
Figure 7 Firm and Total Capacity Trigger Plot With Projected AADF Flows and Necessary Capacity Expansion Improvements 1-17
Figure 8 Firm Capacity Trigger Plot With Unit Processes Capacities 1-18 TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
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Figure 9 Projected Anaerobic Digestion Hydraulic Retention Time (2.6% PS+scum and
2.5% TWAS). 1-19
Figure 10 Projected Anaerobic Digestion Hydraulic Retention Time (3% PS+scum and 5% TWAS) 1-20
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Abbreviations
AA average annual
AADF average annual daily flow
AB aeration basin
ADMM average day maximum month
ADMMF average day maximum month flow
ADMML average day maximum month load
AB aeration basin
BOD biochemical oxygen demand
Carollo Carollo Engineers
cfm cubic feet per minute
City City of Visalia
COD chemical oxygen demand
cu ft cubic foot
deg C degree Celsius
ft feet
GBT gravity belt thickener
GCSD Goshen Community Services District
gpd/sf gallons per day per square feet
gpm gallons per minute
IMLR internal mixed liquor return
lbs/hr pounds per hour
MBR membrane bioreactor
MG million gallons
mgd million gallons per day
mg/L milligrams per liter
MLSS mixed liquor suspended solids
OOS out of service
PE primary effluent
PWWF peak dry weather flow
ppd pounds per day
PS primary sludge
PWWF peak wet weather flow
RAS recycled activated sludge
scfh standard cubic feet per hour
scfm standard cubic feet per minute
sec seconds
SRT solids retention time
TKN total Kjeldahl nitrogen
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TM technical memorandum
TN total nitrogen
TP total phosphorus
TS total solids
TSS total suspended solids
TWAS thickened waste activated sludge
UV ultraviolet
VS volatile solids
WAS waste activated sludge
WDR Water Discharge Requirements
WRF Water Reclamation Facility
WW wastewater
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
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TM 1 NEAR-TERM PROCESS PERFORMANCE
EVALUATION
1.1 Introduction
In recent years, there has been a significant increase in industrial loads, along with increased water conservation efforts in residential wastewater within the City and Goshen. The increased concentrations of wastewater has had a direct impact on the facility which is operating near its maximum capacity when it comes to influent biochemical oxygen demand (BOD) and total suspended solids (TSS). These elevated loadings are putting excessive stress on some of the treatment processes and leading to disruptions and disturbances. The objective of this Facility Plan is to evaluate the existing treatment processes and facilities to develop the framework for improvements required to meet the WRF’s near-term (6-year) needs.
This technical memorandum (TM) provides an overview of the WRF, summarizes the historical and projected influent flows and loads, and summarizes the performance and capacity assessments. These performance and capacity assessments were used to identify near-term capacity improvement projects to serve as the basis for the near-term capital improvement plan.
1.2 Description of Existing Facilities
The City’s WRF was originally built in 1966, and since then, has undergone multiple significant expansions and improvements. In 1995, the City entered into an agreement with the Goshen Community Services District (GCSD) that established the City would accept and treat wastewater discharge from the Community of Goshen. This agreement established maximum limits for flow and BOD and TSS loads that have been modified in subsequent amendments to the agreement.
The Water Discharge Requirements (WDR) state that the WRF has a treatment capacity of 18 million gallons per day (mgd) for dry weather monthly average daily flow. However, during the most recent upgrade project, a phased approach for installing equipment was implemented and structures were designed to handle an average annual daily flow (AADF) of 22 mgd, but wherever practical, the actual equipment installed was designed to handle an AADF of 18 mgd. Therefore, some processes will require equipment expansions to meet the AADF of 22 mgd.
Treatment at the WRF consists of screening, vortex grit removal, primary treatment, secondary treatment with activated sludge and membrane bioreactors, and ultraviolet (UV) disinfection. The treated effluent is discharged to either to Tulare Irrigation District, onsite disposal ponds, or to City-owned Basin No. 4.
Solids processing consists of thickening waste activated sludge (WAS) with gravity belt thickeners (GBTs), anaerobic digestion of primary sludge (PS)/scum and thickened waste activated sludge (TWAS), and dewatering of digested sludge with screw presses. Once the digested sludge has been dewatered, it is transported to onsite sludge drying beds and ultimately disposed by either land application at an approved facility or used as landfill alternative cover.
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
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1.3 Historical Influent Flows and Loads
Daily influent flow and load data was evaluated from January 2018 to April 2023. Figure 1 shows the historical daily and 30-day average influent flow to the WRF. The reported influent BOD and TSS loadings are shown in Figure 2. The reported data shows a significant increase in the raw influent flows and loads (BOD, chemical oxygen demand [COD], and TSS) starting in August 2020 and onwards. Reported influent loads after 2020 have doubled or tripled when compared to the loads prior. Furthermore, the influent ratio of organics (as BOD and COD) to TSS sharply decreased after August 2020, indicating a higher load contribution of inert constituents (see Appendix A).
Through discussions with the City, the observed increase in solids and organic loading to the plant is in part attributable to a higher industrial discharge contribution. To capture this recent increase in industrial loads, the period from August 2020 to April 2023 was selected as the baseline period to calibrate the steady state biological model.
Figure 1 Historical Daily Raw Influent Flow Data
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Figure 2 Historical Daily Raw Load Data for BOD (Top) and TSS (Bottom) A summary of the flows and loads for each year of available data and for the baseline period are presented in Table 1. This data is for the combined influent consisting of both domestic and commercial/industrial flows.
Table 1 Historical Flows and Loads
Condition 2018 2019 2020 2021 2022 2023
Baseline Period
Average(1)
Average Annual
Flow, mgd 10.9 11.1 11.2 11.9 12.0 12.6 11.9
BOD, mg/L 250 253 335 471 554 660 539
BOD, ppd 22,700 23,300 31,300 46,600 55,500 68,700 54,000 COD, mg/L 492 507 708 1,117 1,365 1,402 1,251
COD, ppd 44,600 46,800 66,100 110,600 136,400 146,900 124,000 TSS, mg/L 148 103 313 733 635 907 715
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Condition 2018 2019 2020 2021 2022 2023
Baseline Period
Average(1)
TSS, ppd 13,400 9,500 29,300 72,600 63,500 95,100 71,000 Maximum Month
Flow, mgd 11.2 11.7 11.5 12.4 12.3 13.6 12.4
BOD, ppd 29,500 35,600 43,800 63,600 74,000 82,400 73,000 COD, ppd 48,900 50,000 132,000 156,700 186,900 181,000 175,000 TSS, ppd 25,600 12,900 104,400 103,500 107,100 122,300 111,000 Peak Hourly
Flow, mgd 20.5 19.5 22.0 26.0 21.5 30.0 23.3
Notes:
(1) August 2020 to April 2023 data screened from outliers using a 90-day rolling 2-sigma criterion (95% confidence interval).
Using the data summarized in Table 1, influent flow and load peaking factors were developed. Peaking factors represent the various flow or load conditions as a ratio to the average annual daily flow or load values. The individual peaking factors for each year, as well as the average peaking factors, are summarized in Table 2. The average daily maximum month flow (ADMMF) and peak wet weather flow (PWWF) peaking factors are relatively low and likely due to low inflow and infiltration in the collection system. The BOD, COD, and TSS ADMM load peaking factors are within the expected range for a municipal wastewater treatment facility. Load peaking factors for the 2020 year are higher than usual due to a significant increase in the industrial load contribution after August 2020. Therefore, the load peaking factors prior to 2020 were excluded from the average calculations used for the load projections.
Table 2 Historical Peaking Factors
Condition 2018 2019 2020 2021 2022 2023
Baseline Period
Average
ADMM to AA
Flow 1.03 1.06 1.02 1.04 1.03 1.08 1.05(1)
BOD 1.30 1.52 1.40 1.36 1.33 1.20 1.30(1)
COD 1.10 1.07 2.00 1.42 1.37 1.23 1.34(1)
TSS 1.90 1.35 3.57 1.43 1.69 1.29 1.47(1)
PWW to AA
Flow 1.87 1.75 1.96 2.18 1.78 2.38 2.00(2)
Notes:
(1) The average ADMM peaking factor used for BOD, TSS and COD loads are estimated for the 2021-2023 period. Excludes 2020 because of the sharp increase in loading rates after August 2020, which results in high ADMM peak factors values. 2018 and 2019 data were excluded due to lower industrial loads that differ from current nominal operation. (2) The average PWWF peaking factor used for the influent flow is estimated for the 2018-2023 period.
1.4 Flow and Load Projections
The influent flow and load projections include both domestic and industrial wastewater flows. The equivalent per capita flow and loads were estimated using 2022 census data and historical influent flow TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
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and loads data. The contribution of industrial flows and loads are hence embedded in the estimated equivalent per capita wastewater generation. Therefore, the projected increase in flows and loads from the industrial contributors in the service area are assumed proportional to the population growth.
The flow and load projection assumed the same growth rate, 2.6 percent per year for the City, as what was used in the City’s 2021 Sanitary Sewer System Master Plan. The near-term 2024 flows incorporate the City’s current approved permits/projects and approved development maps, taking into account planned annexations. This equates to an increase of approximately 1,053 equivalent dwelling units (EDU’s) per year, which is approximately 315,000 gallons per day (gpd) increase over 2023. In addition, the GC SD has proposed an additional 203,000 gpd per Amendment 6. For GCSD, the current max flow limit of 360,000 gallons per day (gpd) was used until mid-2024, when it is assumed to increase to 563,000 gpd.
A summary of the projected 2030 flows and loads is shown in Table 3 and shown in Figures 3 and 4. The average annual flow for 2030 is projected to increase to 15.1 mgd, which is 2.6 mgd more than the current 2023 average.
Table 3 Flow and Load Projections Summary
Condition Baseline Period 2030 (6-year Horizon)(1)
Average Annual
Flow, mgd 11.9 15.1
BOD, mg/L 539 660
BOD, ppd 54,000 83,000
COD, mg/L 1,251 1,405
COD, ppd 124,000 177,000
TSS, mg/L 715 910
TSS, ppd 71,000 114,000
Maximum Month
Flow, mgd 12.4 15.8
BOD, ppd 73,000 107,000
COD, ppd 175,000 227,000
TSS, ppd 111,000 168,000
Peak Wet Weather
Flow, mgd 23.3 30.2
Notes:
(1) Wastewater concentrations, flows, loads and peaking factors are projected using average data from August 2020 to April 2023 (baseline period).
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Figure 3 Influent Flow Projections For 2023 To 2030
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Figure 4 BOD And TSS Load Projections For 2023 To 2030
1.5 Existing Treatment Process Performance
This section summarizes the historical performance of the treatment processes. Daily operating data from January 2018 to April 2023 was reviewed for the assessment. In addition to reviewing historical data, discussions were held with operations and maintenance staff and the WRF’s Operations and Maintenance Manual was reviewed to better understand the WRF performance and capacity limitations. Table 4 presents the average daily effluent performance from 2018 to 2023 compared to the effluent discharge limits. As shown in the table, the WRF has had effluent exceedances for daily maximum BOD in June 22nd and 23rd of the year 2022 and monthly average total nitrogen (TN) in August of 2019. The exact cause is unknown. Other than these exceedances, the WRF has performed adequately over the past 5 years to meet the effluent limits.
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Table 4 Effluent Limits and Average Performance
An understanding of the WRF’s unit process performance is critical to determining the treatment capacity.
Based on historical loading and performance, recommended criteria for assessing capacity were developed for each major treatment process to serve as the basis for the process capacity evaluatio n. The historical load and performance of each unit process was compared to the original design criteria and typical design values. The performance of each unit process provides a benchmark for the planning of new facilities and assessing capacity. In some cases, historical performance confirms that original design criteria are appropriate for assessing unit process capacity. In others, above or below average performance warrants adjusting original design criteria for assessing capacity. For each unit process, recommended design criteria are identified for use in the capacity assessment.
Table 5 summarizes the results of the performance evaluation.
Effluent
Parameter Units Effluent Limit
Effluent Data
2018 2019 2020 2021 2022 2023
BOD mg/L
Annual
Average N/A 4.1 4.2 3.9 1.8 2.6 2.7
Monthly
Avg. 10 6.7 8.7 5.2 2.8 6.4 3.8
Daily Max 20 14.0 18.0 18.0 7.1 23.0 20.0
TSS mg/L
Annual
Average N/A 2.1 1.5 1.0 0.8 1.0 1.7
Monthly
Avg. 10 3.8 4.4 1.2 1.7 1.2 2.4
Daily Max 20 16.0 7.2 2.4 6.6 3.4 3.2
TN mg/L
Annual
Average N/A 5.9 6.8 5.4 4.5 4.6 5.0
Monthly
Avg. 10 9.3 14.0 6.8 5.7 6.1 5.4
Daily Max N/A 10.0 18.0 11.0 8.4 8.7 6.6
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Table 5 Unit Process Performance and Capacity Criteria
Process Design Parameter Units Original Design
Capacity
Average of Daily
Performance from
2020-2023
MOP-8 or Typical
Values
Recommended Criteria
for Capacity Analysis
Headworks
Mechanical Bar
Screens
Flowrate mgd 2 at 47, each
47 firm, 94 installed
30.0 PWWF Sufficient firm capacity
(i.e., 1 unit OOS) for
PWWF
47 firm
Influent Pumping
Station
Flowrate mgd 2 at 7, each
4 at 11, each
47 firm, 58 installed
11.9 AADF
30.0 PWWF
Sufficient firm capacity
(i.e., 1 unit OOS) for
PWWF
47 firm
Grit Tanks Flowrate mgd 4 at 12, each
36 firm
11.9 AADF
30.0 PWWF
Sufficient firm capacity
(i.e., 1 unit OOS) for
PWWF
36 firm
Primary Clarifiers
Overflow Rate at AADF gpd/sf 850 465 800-1,200 850
Overflow Rate at
PWWF
gpd/sf 1,705 969 2,000-3,000 1,705
Percent BOD₅
Removal
% 30-35 40 25-40 30-35
Percent TSS Removal % 60-65 78(1) 50-70 78(1)
Primary Effluent mg/L BOD = 260, COD =
500, TSS = 125(2)
At Max Month Load
during AADF
BOD = 400, COD =
725,
TSS = 173
Variable depending on
WW strength and
primary treatment
performance
BOD = 400, COD =
725,
TSS = 173
Primary Sludge TS % 4 2.5 3-4 2.5
Primary Sludge Pumps Flowrate gpm 4 at 100, each
200 firm, 400 installed
60 AAD
83 ADMM
Sufficient firm capacity
(i.e., 1 unit OOS) for
ADMM
200 firm
Inter-Stage Transfer Pumping Station
Inter-Stage Pumps Flowrate mgd 3 at 22, each
44 firm, 66 installed
30.0 PWWF(3) Sufficient firm capacity
(i.e., 1 unit OOS) for
PWWF
44 firm
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Process Design Parameter Units Original Design
Capacity
Average of Daily
Performance from
2020-2023
MOP-8 or Typical
Values
Recommended Criteria
for Capacity Analysis
Fine Screens
Fine Screens Screen Capacity mgd 4 at 15, each
45 firm, 60 installed
30.0 PWWF Sufficient firm capacity
(i.e., 1 unit OOS) for
PWWF
45 firm
Membrane Bioreactor (MBR) System
Aeration Basins
(MBRs)
MLSS (ABs) mg/L 8,000 7,300 6,000-8,000 8,000
MBR System Minimum Month MLSS
Temp.
Deg C Not Available 20.4 Variable depending on
climate
20.4 SRT(4) Days 8-12 24.0 8-12 10.0
Total Peak Day Airflow scfm 5 at 7,769, each
31,076 firm, 38,845
installed
Not Available Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day airflow
31,076 firm
MLSS (MBRs) mg/L 12,000 10,100 10,000-12,000 10,000
Membrane Cassettes Flux at AADF mgd 10 trains at 2, each 18 firm, 20 installed
11.9 Sufficient firm capacity
(i.e., 1 unit OOS) for
AADF
18 firm
Flux at PWWF mgd 10 trains at 4, each
36 firm, 40 installed
30.0 Sufficient firm capacity
(i.e., 1 unit OOS) for
PWWF
36 firm
RAS Pump Station Flowrate mgd 4 at 26, each
78 firm, 104 installed
30.0(5) Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day load
78 firm
WAS Pumps Flowrate gpm 2 at 500, each
500 firm, 1,000
installed
130(6) Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day wasting
500 firm
Permeate Pumps Flowrate gpm 10 at 3,930, each
35,370 firm, 39,300
installed
20,800 Sufficient firm capacity
(i.e., 1 unit OOS) for
PWWF
35,370 firm
UV Disinfection System
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Process Design Parameter Units Original Design
Capacity
Average of Daily
Performance from
2020-2023
MOP-8 or Typical
Values
Recommended Criteria
for Capacity Analysis
Flowrate mgd 28.8 firm 30.0 (PWWF) Sufficient firm capacity (i.e., 1 unit OOS) for
PWWF
28.8 firm
WAS Thickening
Gravity Belt Thickeners
(GBT)
Hydraulic Loding gpm 2 at 500, each
500 firm, 1,000
installed
130(6) Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day wasting
500 firm
Solids Loading lbs/hr 2 at 3,000, each
3,000 firm, 6,000
installed
640(7) Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day wasting
3,000 firm
TS % 5 2.4 5-6 2.4
Solids Capture % 90 93 90-95 90
Thickened Sludge
Pumps
Flowrate gpm 2 at 100, each
100 firm, 200 installed
50 Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day wasting
100 firm
Anaerobic Digesters
HRT days 19.5 All Units
25.5 (AA)
17.4 (ADMM)
All Units w/ No. 8 OOS
17 (AA)
12.1 (ADMM)
15 days (Class B
Biosolids)
15 days (largest unit
OOS)
VS Loading at AADF ppdVS/cu ft Not Available 0.07 0.12-0.18 0.12 (largest unit OOS) VS Loading at ADMMF ppdVS/cu ft Not Available 0.11 0.15-0.20 0.17 (largest unit OOS) VS Reduction % Not Available 50 50-65 50
Sludge Transfer Pumps Flowrate gpm 2 at 300, each
300 firm, 600 installed
125 AADF
180 ADMM
Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day sludge flows
300 firm
Sludge Dewatering and Drying
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Process Design Parameter Units Original Design
Capacity
Average of Daily
Performance from
2020-2023
MOP-8 or Typical
Values
Recommended Criteria
for Capacity Analysis
Dewatering Feed
Pumps
Flowrate gpm 3 at 150, each
300 firm, 450 installed
125 AADF
180 ADMM
Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day sludge flows
300 firm
Screw Press
Dewatering Units
Flowrate gpm 2 at 110, each
110 firm, 220 installed
125 AADF
180 ADMM
Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day sludge flows
110 firm
Solids Loading lbs/hr 2 at 1,100, each
1,100 firm, 2,200
installed
950 AADF
1,450 ADMM
Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day sludge flows
1,100 firm
Dewatering Screw
Conveyors
Flowrate cu ft/hr 420 96 Sufficient firm capacity
(i.e., 1 unit OOS) for
peak day sludge flows
420 firm
Digester Gas Handling and Renewable Power Generation System (RPGS) Waste Gas Flare
System
Maximum Flowrate scfh 21,250 11,000 Sufficient firm capacity (i.e., 1 unit OOS) for
peak day biogas
production
21,250
Notes:
(1) Primary Clarifier BOD and TSS removal rates are estimated through a mass balance of the solids based on measured flows (raw influent, primary sludge, primary scum) and concentrations (raw influent, PS, primary scum, primary effluent). The recommended criteria for capacity analysis have been set at the removal percent estimated through the available primary treatment data.
This number is significantly higher than typical. Carollo recommends that the City conduct further investigation of the influent sample location and whether a representative sample is being collected.
(2) Primary effluent BOD, COD, and TSS design concentrations were estimated using the original raw influent design criteria and typical design PC removal percentages (35% BOD, 65% TSS).
COD was estimated using historical primary effluent COD to BOD ratios prior to August 2020 (3) PWWF at inter-stage pump station flow was assumed to be the same as the influent flow. (4) Total SRT of the MBR system is calculated using total volume (basins and membrane tanks), measured RAS TSS, measured MLSS in the aerobic tanks, and estimated WAS flows. (5) No RAS data was available for the 2020-2023 period. Reported RAS data was estimated based on a 250% target value of the influent flow rate, as reported by the plant’s operations staff. (6) No WAS data was available for the 2020-2023 period. Reported WAS data was estimated based on an average 130 gpm value, as reported by the plant’s operations staff. (7) The loading to the GBTs was estimated based on an average WAS flow of 130 gpm and the actual 2020-2023 TSS concentration data.
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1.6 Biological Model
A steady state model was developed for the City’s WRF using Envirosim’s BioWin software, version 6.2.
The scope of the model was limited to primary treatment, secondary treatment, anaerobic digestion, and the sludge handling and processing units. The model was used to determine near-term capacity bottlenecks.
The model was developed using custom-configured unit process modules that reflect the WRF’s existing configuration and operation. Physical dimensions (volume and depth or area and depth) of each unit process and flow rates such as raw influent, primary effluent (PE), RAS, internal mixed liquor return (IMLR) and WAS were inputs to the model. Other historical process data collected at different stages of the WRF treatment processes was utilized to calibrate and validate the biological model. The configuration of the model is shown in Figure 5.
The aeration basins were modeled as a series of six zones, as shown in Figure 5. Zones 1 through 3 are anoxic zones, while Zones 4 through 6 represent the aerobic zones. Each zone in the model represents the overall treatment capabilities of the four parallel treatment trains (i.e., total volume, number of diffusers, etc.). The membrane tanks are modeled using one unit process module that is equivalent to ten of the membrane tanks operating in parallel.
Figure 5 BioWin Configuration for WRF
1.6.1 Summary of Model Calibration Results
For the model calibration, flow inputs such as the influent, primary sludge (PS), WAS, and TWAS, as well as influent concentrations such as COD, total Kjeldahl nitrogen (TKN), and total phosphorus (TP), were set to match the average from the calibration period. The influent COD fractions were adjusted so that model outputs match the plant data as close as possible. The calibration results for the secondary treatment process were good, as the model predictions match the plant’s reported performance within 10 percent,
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which is considered sufficient for planning and design of wastewater facilities. The full calibration data is provided in detail in Appendix C. One issue was identified during the calibration process when performing a solids mass balance around the primary clarifiers. The predicted primary sludge mass loading rates from the calibrated model were significantly higher than the reported data. A discussion of this primary sludge solids mass balance is included in the section below.
1.6.2 Solids Mass Balance
The model predicts significantly more primary sludge production than reported in the plant data. This can be seen when comparing the model results to historical plant data for the primary sludge flow rates and concentrations. Some potential causes for this primary sludge solids mass balance discrepancy are discussed below.
▪ Influent Sample: Composite raw influent samples are collected through an autosampler and sent to a local laboratory for analysis. If the sample is not representative and contains more solids than what is actually entering the plant, the model would predict more sludge than is reported. ▪ PS Flow Meters: The PS flow rate is recorded through flow totalizers that are determined based on the cycling time and the pump run time during each cycling event. Issues with flow meter calibration can impact the estimated PS solids loads. However, the City regularly calibrates these flowmeters and checked them again as part of this study, and they are believed they are sufficiently accurate. ▪ PS TSS Concentration: Grab samples are collected for the TSS concentration of the PS and then sent to a local laboratory for analysis. A special sampling campaign was performed to compare sampling methodologies (i.e., grab vs. composite sampling). For all primary clarifiers, both methodologies showed good consistency in the TSS accuracy (0 to 10 percent difference between grab and composite sampling).
The most likely explanation for the mass balance discrepancy is that the influent sample is not representative. This is believed for the following reasons:
▪ Plant staff have QA/QC’d the PS flow meter calibration as well as the PS TSS concentration. The PS TSS concentration has been consistent throughout the review period. ▪ The primary effluent sample is believed to be representative since it is well calibrated to the secondary process module in the model.
▪ The PS, WAS, and digester data (% TS, % VS, and gas production) are consistent with each other, suggesting the solids data is reliable. If PS loads to the digester were actually as high as the model predicts, the digesters would be operating at extremely low HRTs (less than 10 days) and would likely have failed by now.
▪ Primary clarifier TSS and BOD removal are 78 and 40 percent, respectively. This is significantly higher than typical values and suggests either the influent or primary effluent sample is not representative.
Since the primary effluent sample is believed to be representative, it’s possible the influent sample is not.
We recommend that the City conduct further investigation of the influent sample location and whether a representative sample is being collected.
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1.7 Capacity Analysis
This section summarizes the results of the process capacity evaluation. Capacities were estimated for each unit process and were dependent on a range of parameters including flow, influent wastewater characteristics, treatment objectives, process configurations, operational setpoints, and desired redundancy. The capacities are based on the recommended criteria in Table 5.
For the secondary process and solids handling facilities, the calibrated process model was used to simulate process conditions under maximum month loading. The model was used to determine the influent flow at which the recommended (or limiting) criteria in Table 5 is seen. The equivalent AADF capacity is then considered for the scheduling of near-term capacity improvements needs based on future AADF flow projections.
1.7.1 Capacity Analysis Summary
Figure 6 and Table 6 present the estimated capacity for each unit process at the City’s WRF. As shown in Figure 6 and Table 6, all unit processes have sufficient capacity to handle the estimated 2030 projections except for the UV disinfection system, anaerobic digestion process, and dewatering screw press units, which are discussed further in the following sections.
Figure 6 Unit Process Capacities
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Table 6 Unit Process Capacities
Process Controlling Condition Capacity (mgd) 2030 Projected Flow (mgd) Firm Capacity
Deficit (mgd)
Mechanical Bar Screens PWWF 47(1) 30.2 0
Influent Pump Station PWWF 46.9(1) 30.2 0
Grit Removal PWWF 36(1) 30.2 0
Primary Clarification AADF
PWWF
17.5(1)
44(1)
15.1 30.2
0 0
Inter-Stage Pump Station PWWF 44.4(1) 30.2 0
Fine Screens PWWF 45(1) 30.2 0
MBR System AADF
PWWF
16.3(2)
36(2)
15.1 30.2
0 0
Membrane Tank Permeate
Pumps PWWF 50.9(1) 30.2 0
UV Disinfection PWWF 28.8(1) 30.2 -1.4
Digesters AADF 7.8(3) 15.1 -7.3
Sludge Dewatering AADF 7.1(3) 15.1 -8.0
Notes:
(1) Firm capacity: largest unit out of service.
(2) Total capacity: all units in service.
(3) Capacity was developed based on firm capacity and current operating conditions with an average feed concentration of 2.5% solids to the digesters.
In addition, the overall firm and total capacity of the WRF were plotted against the projected flows and are shown in Figure 7. This is further broken down in Figure 8 that shows the firm capacity, which is the capacity with the largest unit is out of service, in relation to the different unit processes capacities and delineates which unit process limits the firm capacity. Currently, the WRF firm capacity is limited by the dewatering process and anaerobic digestion.
The first recommended near-term project is to replace the TWAS pumps to allow TWAS to be thickened to an average of 5 percent TS and reduce the volume of sludge being fed to the digesters. Since the dewatering process and digesters are currently hydraulically limited, reducing the volume of sludge fed to them will directly increase their available capacities. After replacing the TWAS pumps, the dewatering process is still the limiting process for the WRF firm capacity and therefore, a dewatering process capacity expansion project should install a third screw press. After installation of the third screw press, the digesters become the limiting process and a new digester should be constructed. The last recommended near-term project is to expand the capacity of the UV system to meet the projected 2030 PWWF.
After all four recommended near-term projects have been implemented, the WRF becomes capacity limited by the MBR system at 16.3 mgd, which is greater than the projected 2030 flow so the WRF would then have sufficient near-term capacity.
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Figure 7 Firm and Total Capacity Trigger Plot With Projected AADF Flows and Necessary Capacity Expansion Improvements
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Figure 8 Firm Capacity Trigger Plot With Unit Processes Capacities
1.7.2 UV Disinfection System
As shown in Table 6 above, the capacity of the UV disinfection system does not have sufficient firm capacity to meet the projected 2030 PWWF and will need to be expanded. The existing system was constructed with space allocated for installing four additional modules in the existing channels. Installing these modules would increase the UV system’s firm capacity to be able to meet the projected 2030 flows.
Refer to TM 4 – Near-Term Project Descriptions for more information on the UV expansion project.
1.7.3 Anaerobic Digestion System
For the near-term horizon, the digesters have sufficient treatment capacity in terms of volatile solids (VS) loading but are limited by the hydraulic retention time (HRT). The HRT of the digesters was estimated based on the projected sludge flows. PS and scum flow was assumed to be proportional to the raw influent flows based on historical ratios from 2020 to 2023. Although TWAS flows for the calibration of the biological model were estimated based on WAS flows needed to match an SRT of 10 days, the TWAS flows used for digester HRT projections were conservatively assumed proportional to the to the raw influent flows based on historical ratios from 2020 to 2023.
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Based on the 2023 average sludge concentrations (2.6 percent PS+scum and 2.5 percent TWAS) and with Digester No. 8 OOS, the ADMMF HRT capacity of the digesters is below the minimum 15-day threshold for achieving Class B biosolids as seen in Figure 9.
Figure 9 Projected Anaerobic Digestion Hydraulic Retention Time (2.6% PS+scum and 2.5% TWAS).
By further thickening the PS + scum and TWAS streams to average concentrations of 3 percent and 5 percent, respectively, the sludge feed flows to the digesters could be reduced and restore some digestion capacity. The HRT of the digesters with these thicker sludge feeds is shown in Figure 10. As shown, an additional digester will need to be constructed by 2027 to meet the 15-day HRT requirement with the largest digester out of service. Refer to TM 4 – Near-Term Project Descriptions for more information on replacing the TWAS pumps and the digester capacity expansion project.
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Figure 10 Projected Anaerobic Digestion Hydraulic Retention Time (3% PS+scum and 5% TWAS)
1.7.4 Dewatering System
As shown in Table 6 above, the capacity of the dewatering system is not sufficient to meet the projected 2030 sludge flows. In addition, the dewatering system does not have enough firm capacity to meet the current peak sludge flows and the plant must run both screw presses to dewater all of the sludge. In order to be able to take a unit out of service, the dewatering system should be expanded with a third screw press to have sufficient firm capacity to meet the projected sludge flows and loads. Refer to TM 4 – Near- Term Project Descriptions for more information on the dewatering expansion project.
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WATER RECLAMATION FACILITY - FACILITY PLAN
APPENDIX A FLOW AND LOAD DATA
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN
Different datasets of the Visalia WRF operations were used as inputs of the biological model and to compare the model outputs during the calibration phase. Daily data mainly included the operational variables such as flows (influent, primary sludge and scum and TWAS) and water quality parameters (TSS COD, and BOD₅. Daily water quality parameters such as ammonia, nitrate, TKN, TP, alkalinity, were collected for a few weeks after the start of the project to augment the information regarding the influent characterization.
The input and output data of the biological model was screened from outliers using a 90-day rolling 2- sigma criterion (95% confidence interval) and were then reviewed and analyzed for periods of operations that diverged from nominal operating conditions. Outlier data was flagged and was not considered in the biological model calibration.
Figure 1A.1 Historical Daily Raw Influent BOD Concentrations
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
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Figure 1A.2 Historical Daily Raw Influent COD Concentrations
Figure 1A.3 Historical Daily Raw Influent TSS Concentrations
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN
Figure 1A.4 Historical BOD Over TSS Ratios
Figure 1A.5 Historical COD Over TSS Ratios
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
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Figure 1A.6 Historical Influent And Effluent pH
Figure 1A.7 Historical Effluent TSS
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN
Figure 1A.8 Historical Effluent BOD
Figure 1A.9 Historical Effluent COD
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
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Figure 1A.10 Historical Effluent Nitrogenous Compounds
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
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APPENDIX B BIOLOGICAL MODEL INFORMATION
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN
Table 1B.1 Biological Model Calibration Table
Variable Units
Data (average over
baseline period)
Coefficient of
Variation of Data (1)
Simulated w/
biological model
Data/Model
Difference
Raw Influent
Flow MGD 12 7% 12 0.1%
TSS mg/L 715 62% 668 6.6%
BOD mg/L 539 36% 530 1.7%
COD mg/L 1,251 33% 1252 0.1%
TP (3) mgP/L 18.3 25% 18.1 0.7%
NHx-N (3) mgN/L 50.3 25% 47.8 4.9%
Temperature C 24 12% 24 0.0%
pH - 6.8 4% 6.8 0.0%
Primary Clarifiers
PS + Scum Flow MGD 0.1070 0.107 0.0%
Effluent TSS mg/L 128 50% 142 11%
Effluent BOD mg/L 294 25% 291 1.0%
Effluent COD mg/L 588 16% 553 6.0%
Sludge TSS mg/L 24,801 30% 58,782 137%
Sludge VSS (2) mg/L 22,174 29% 49,851 125%
Aeration Basins
MLSS mg/L 7,299 15% 7,198 1.4%
MLVSS mg/L 5,815 15% 5,515 5.2%
Airflow cfm missing 14,320
DO mg/L 2.13 35% 2 6.1%
Membrane Tanks
MLSS mg/L 10101 21% 10,061 0.4%
MLVSS mg/L 7,970 24% 7,706 3.3%
Airflow ppd missing 11,056
DO mg/L 2.1 6.1% 2.0 6.1%
WAS TSS mg/L 9,727 15% 10,061 3.4%
WAS VSS mg/L 7,927 13% 7,706 2.8%
GBT Filter
TWAS Flow MGD 0.08 39% 0.08 4.1%
TWAS TSS mg/L 24,015 20% 23,512 2.1%
TWAS VSS mg/L 18,794 19% 18,008 4.2%
Effluent TSS mg/L 678 134% 683 0.7%
Effluent VSS mg/L 554 73% 523 5.6%
Digesters
Digester TSS mg/L 15,217 6% 28,478 87.1%
Reactor VSS mg/L 10,727 9% 20,428 90.4%
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
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Variable Units
Data (average over
baseline period)
Coefficient of
Variation of Data (1)
Simulated w/
biological model
Data/Model
Difference
HRT(2) days 17 17 2.9%
Biogas Production cfd 264,403 15% 406,166 53.6%
Screw Press
Dewatering
Cake TSS % 15.6% 9% 15.8% 1.5%
Cake VSS % missing 11.4%
Screw Pressate TSS mg/L 307 81% 605 97.3%
Screw Pressate VSS mg/L missing 9% 434 1.5%
Effluent
BOD mg/L 2.57 3.0 (4) 0.79 1.78
COD mg/L 28.1 81% 29.25 4.2%
TSS mg/L 1.12 0.68 (4) 0.00 1.12 (4)
NHx-N mg/L 0.90 1.34 (4) 0.04 0.86 (4)
TKN mg/L 1.52 0.94 (4) 1.40 0.12 (4)
NO3-N mg/L 3.09 0.92 (4) 5.22 2.13 (4)
TN mg/L 4.54 1.18 (4) 6.63 2.09 (4)
TP mg/L 6.73 0.90 (4) 6.89 0.16 (4)
pH - 7.08 3% 6.72 5.1%
Notes:
1. The coefficient of variation shows the extent of variability in relation to the mean of the data. The coefficient of variation iscomputed by dividing the standard deviation by the mean.
2. The estimates for the hydraulic retention time of the digesters do not account for digester no. 8.
3. Data averages are computed using only 4 data samples, following a special sampling campaign.
4. The variation of the data and the difference between data and simulated values are shown here in absolute terms.
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
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APPENDIX C ANAEROBIC DIGESTER PERFORMANCE
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
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Primary sludge, scum, and thickened waste activated sludge (TWAS) undergo anaerobic digestion, a process designed for mesophilic stabilization of the solids and biogas generation. The solids are distributed across eight existing digesters. Of these eight digesters, No. 1 and No. 2 have an operating volume of 0.26 million gallons (MG) each, No. 3 through No. 7 have 0.52 MG each, and No. 8 has 1.94 MG (1.38 MG designed for active digestion and 0.55 MG for storage).
Following the 2017 improvements, the plant’s typical de-gritting of the digesters through gravity wasting has been limited. In April 2023, Digester No. 4 was taken out of service for maintenance and inspected.
The inspection revealed a significant accumulation of grit. It is expected that the other digesters also have significant grit accumulation that reduces the active volume of the digester and thus, reduces the overall HRT of the anaerobic digestion system.
Figure 1C.1 Historical Sludge Flows
TECHNICAL MEMORANDUM 1 – NEAR-TERM PROCESS PERFORMANCE EVALUATION FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN
Figure 1C.2 Historical VFA Profiles For Digesters No. 1 Through No. 7
Figure 1C.3 Historical Active Digester Volumes And Estimated HRTs
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 2
Condition Assessment
FINAL / February 2024
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 2
Condition Assessment
FINAL / February 2024
This document is released for the purpose of information exchange review and planning only under the authority of Kyle T. Leonard, February 2024, CA PE 86011 .
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN i
Contents
TM 2 CONDITION ASSESSMENT 2-1
2.1 Introduction 2-1
2.1.1 Overview 2-1
2.1.2 Project Goals 2-1
2.2 Condition Assessment Methodology 2-1
2.2.1 Introduction 2-1
2.2.2 Condition Assessment Rating Scale 2-1
2.2.3 Determining Reinvestment Year 2-2
2.3 Preliminary Treatment 2-2
2.3.1 Condition and Performance Assessment 2-2
2.3.2 Conclusions and Recommendations 2-5
2.4 Primary Treatment 2-5
2.4.1 Condition and Performance Assessment 2-5
2.4.2 Conclusions and Recommendations 2-8
2.5 Secondary Treatment 2-9
2.5.1 Condition and Performance Assessment 2-9
2.5.2 Conclusions and Recommendations 2-16
2.6 Tertiary Treatment 2-17
2.6.1 Condition and Performance Assessment 2-17
2.6.2 Conclusions and Recommendations 2-20
2.7 Solids Handling 2-20
2.7.1 Condition and Performance Assessment 2-20
2.7.2 Conclusions and Recommendations 2-23
Appendices
APPENDIX A CONDITION ASSESSMENT SUMMARY TABLE
Tables
Table 1 General Condition Scores 2-1
Figures
Figure 1 Gates in Grit Basins – Corroded Hand Crank 2-3 Figure 2 Septage Receiving Station – Cracked Concrete 2-4 Figure 3 Effluent Gates – Corrosion on Hand Cranks 2-9
Figure 4 Scum Box No. 1 – Corrosion on Piping 2-8
Figure 5 Braced Frame near MBT -Corrosion at Brace and Gusset Connection 2-13 Figure 7 RAS Pump – Sludge Spillage 2-16
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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Figure 8 Wash Water Booster Pump - Corroded 2-21
Figure 9 Screen Manhole Under Screw Presses – Location of Overflows 2-23
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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Abbreviations
Carollo Carollo Engineers
EUL estimated useful life
ft feet
MBR membrane bioreactor
MG million gallons
mgd million gallons per day
mg/L milligrams per liter
psi pounds per square inch
RAS recycled activated sludge
RUL remaining useful life
SCADA supervisory control and data acquisition
TWAS thickened waste activated sludge
WAS waste activated sludge
WRF Water Reclamation Facility
WWTP wastewater treatment plant
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-1
TM 2 CONDITION ASSESSMENT
2.1 Introduction
2.1.1 Overview
This Technical Memorandum (TM) presents the findings and recommendations of the condition assessment performed for Visalia’s Water Reclamation Facility (WRF). The assessment includes evaluations for mechanical, structural, and electrical components of various assets at the WRF.
2.1.2 Project Goals
The goals of this condition assessment include the following:
• Evaluate the condition of each asset to identify system deficiencies. • Develop a list of rehabilitation and replacement needs for the near- and long-term time horizons. • Estimate remaining service life.
2.2 Condition Assessment Methodology
2.2.1 Introduction
This section provides background for how the assets at the WRF were scored and the rating system that dictated the scores. Additionally, the methodology for determining the asset’s ultimate remaining useful life (RUL) and the reinvestment year is described.
2.2.2 Condition Assessment Rating Scale
A visual condition assessment was performed for mechanical, structural, and electrical components of assets, which were then assigned a condition-based assessment score. The condition scoring (condition and performance) is based on a scale of one to five as described in Table 1.
Table 1 General Condition Scores
Condition or Probability
of Failure Score General Description Percent Life Consumed 1 (Best) Good: Asset is in good condition (no defects). 0 - 39 2 Acceptable: Asset has minor defects. 40 - 64
3 Fair: Asset has significant defects that will affect reliability or efficiency. 65 - 79 4 Poor: Asset is highly unreliable or inefficient. 80 - 19 5 (Worst) Failed: Asset is no longer able to function in its current condition. 90 - 100
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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2.2.3 Determining Reinvestment Year
The condition-based scores and installation dates were used to determine when assets should be replaced or rehabilitated, which is referred to as the reinvestment year. To calculate this, the estimated useful life (EUL), RUL, condition-based scores, and installation dates were needed.
The EUL is a set number of years associated with a specific asset that indicates the typical lifetime of the asset. For example, a pump has an EUL of 20 years while a grinder has an EUL of 15 years. The RUL is a calculated time period, also in years, which uses the condition-based scores. To compute the RUL, the upper limit of the percent life consumed column in Table 1 was multiplied by the asset’s EUL then subtracted from the EUL.
The reinvestment year was then calculated using one of two ways: using the condition-based score from the field inspection or using the installation date of the asset. These methods are described further below:
Method 1- Field Inspection: The condition-based scores were used to calculate the estimated RUL as described above. The RUL was then added to 2023 – the year the condition assessment was performed – to determine the reinvestment year.
Method 2 - Installation Date: This method does not rely on inspecting the assets in the field and instead only uses the installation date and EUL. The reinvestment year is obtained by adding the EUL to the installation year.
Each asset’s reinvestment year was calculated both ways, and the project team determined which reinvestment year to use based on the asset’s criticality. For example, if the asset was a redundant pump to a critical process, then the minimum reinvestment year was used. For structures, the maximum reinvestment year was used. This is because the EUL is 50 years, but most of the structures at the WRF are in good to acceptable condition even though they exceed the 50-year lifespan for some structures. It is not recommended to tear down the structures that surpass the EUL and rebuild them though. Instead, another structural inspection should be performed in 10 years.
Asset reinvestment years and scores can be seen in Appendix A.
2.3 Preliminary Treatment
Several processes are included in preliminary treatment. The project team assessed the headworks, grit removal, biofilter, and septage receiving station areas. As mentioned previously, field inspections resulted in scoring related to mechanical, structural, and electrical components in areas as appropriate.
2.3.1 Condition and Performance Assessment
2.3.1.1 South Diversion Structure
Structural: Based on feedback from the City, this structure is in failed condition. The City indicated that exposed rock was present in the wall when they cored it for a new drain line. Improvements to this structure are needed.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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CITY OF VISALIA
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2.3.1.2 Headworks
Mechanical: Overall, the mechanical equipment is in acceptable or good condition with the exception of the influent gates and washer compactor. City staff indicated that the influent gates do not seal , and the hydraulic system has leaks, which will need to be repaired. Corrosion could be seen on both the influent gates and washer compactor as well.
Structural: Overall, the headworks building is in acceptable condition. No structural movement or any major deterioration is observed.
Electrical: Electrical equipment is in good and acceptable condition. Two of the six raw sewage pump VFD cabinets have been recently replaced while the other four are original. City staff has indicated that they have not had any issues with the equipment. There was some corrosion on the instruments and components of the raceway system, in the room with the bar screens.
2.3.1.3 Grit Removal
Mechanical: The grit removal equipment is generally in acceptable condition; however, corrosion was observed in the field, as seen on the hand cranks and gearboxes of the gates in Figure 1. The grit drive and the motors and piping of the grit pumps and classifiers need to be recoated to provide better protection of the equipment.
Figure 1 Gates in Grit Basins – Corroded Hand Crank
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Structural: Overall, the grit basins are in acceptable condition. Minor cracks on the floor are present, but these are mostly hairline cracks with no impact to the structure.
Electrical: There are some scratches and rust forming on the local control panels and their mounting brackets. The overall condition of the electrical equipment is good, with no reported issues from staff.
2.3.1.4 Biofilter
Mechanical: Both fans and the biofilter media are in good condition. However, the typical useful life of biofilter media is 10 years, which was last replaced in 2017. Replacing the media should be considered in the near future.
Structural: Overall structural condition is in good condition. Minor stains are at the anchor location. No major issues found.
Electrical: There was visible rust at the top of the bucket door in the second section of the MCC. No issues reported from city staff. The electrical equipment is in good condition.
2.3.1.5 Septage Receiving Station
Structural: The wall at the septage receiving station has damage to it seen in Figure 2. This may be due to a truck hitting the structure while backing up. The rest of the structure appeared to be in good condition, but overall, the structure is only in acceptable condition. Repair is recommended.
Figure 2 Septage Receiving Station – Cracked Concrete
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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2.3.2 Conclusions and Recommendations
2.3.2.1 Mechanical
Generally, the mechanical equipment is in acceptable condition. However, some improvements are needed. The influent gates need to be sealed better since the hydraulic system has leaks. The biofilter’s media is approaching its 10-year lifespan and should be replaced soon. Additionally, a majority of the equipment has corrosion, which should be addressed with a coating and painting job.
2.3.2.2 Structural
The structures in this area are in good to acceptable condition with exception of the South Diversion Structure, which was scored as failed condition based on feedback from City staff. Improvements to the South Diversion structure are needed. Additionally, the septage receiving station was observed to have cracking, which could have been caused by a truck. As mentioned above, it is recommended to repair the structure where the crack is. No other structures need to be repaired.
2.3.2.3 Electrical
City staff have not indicated any issues with finding replacement parts for MCC H. Obtaining replacement parts will be a future issue and consideration should be made in replacing the MCC to avoid possible lengthy downtime in the future due to difficulty in finding replacement parts. The same considerations should be made for the VFD cabinets that have not been replaced. Arc flash stickers indicate that the previous study was done about 5 years ago, so an arc flash study is due.
2.4 Primary Treatment
This section includes the assessments performed for the Flow Split Structure, Primary Distribution Box A And B, the Primary Sedimentation Basins and Associated Equipment, and Scum Box No. 1 and No. 2 . Like the previous section, assessments for the mechanical, structural, and electrical components are included as needed.
2.4.1 Condition and Performance Assessment
2.4.1.1 Flow Split Structure
Mechanical: The piping at this structure are generally in acceptable condition. Corrosion was observed on some of the piping by the structure, which can be seen in Figure 3. This piping should be recoated.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
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Figure 3 Piping by the Flow Split Structure
Structural: Overall, the structure is in good condition. Minor cracks are present, but these are mostly hairline cracks with no impact to the structure.
2.4.1.2 Primary Distribution Box A and B
Structural: Overall, the structure is in acceptable condition. Primary Distribution Box B can be seen below in Figure 4.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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CITY OF VISALIA
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Figure 4 Primary Distribution Box B
2.4.1.3 Primary Sedimentation Basins (1, 2, 3, 4, and 5) Mechanical: The basins along with the associated equipment are in good to fair condition. The effluent troughs for all the primary sedimentation basins, except Primary Sedimentation Basin 5, are in fair condition, meaning significant defects were observed in the fields. The scum skimmers for Primary Sedimentation Basin 4 are also in fair condition. Corrosion was seen on all the sludge collectors, scum skimmers, and effluent troughs of the primary sedimentation basins.
Structural: Minor cracks and spalls are on the rebate at gratings, but the overall condition is acceptable.
Electrical: The electrical equipment is in good condition. Ther were no visible defects on the local control stations enclosures, conduits, and the mounting hardware. City staff indicated they have not had any issues with the electrical equipment.
2.4.1.4 Scum Box No. 1 and No. 2
Mechanical: Both scum boxes are in fair condition with corrosion seen on the piping, grinders, and pumps.
Scum Box No. 1’s piping is in poor condition, however. It is recommended to replace the piping in Scum Box No. 1.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-8
Figure 5 Scum Box No. 1 – Corrosion on Piping
Structural: Condition of the structure is good. Minor stains on the wall will not impact the adequacy of the structure.
Electrical: The electrical equipment is in good and acceptable condition. There were no defects visible on the primary sludge pump local control stations, conduits, and mounting hardware. There is some visible rust on the ferrous chloride pump enclosure, conduits, and mounting equipment. City staff have indicated that they have not experienced issues with the electrical equipment.
2.4.2 Conclusions and Recommendations
2.4.2.1 Mechanical
Similar to the preliminary treatment section, most of the equipment is in acceptable or fair condition with exception of Scum Box No. 1’s piping, which was in poor condition. It is recommended to replace this piping soon. Additionally, most equipment was noted to have corrosion; a coating and painting project is recommended.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-9
2.4.2.2 Structural
All structures are in good and acceptable condition. There are no reports of movement or settlement.
Minor cracks are present, but these are mostly hairline cracks with no impact to the structure.
2.4.2.3 Electrical
Electrical equipment is in good and acceptable condition. City staff did not report experiencing any issues with the electrical equipment. Arc flash stickers indicate that the previous study was done about 5 years ago, so an arc flash study is due.
2.5 Secondary Treatment
This section includes assessments for junction boxes, the inter-stage pump station, fine screen channels, flow distribution boxes, aeration basins and blowers, membrane bioreactor (MBR) system, MBR blower building, chemical area, and the recycled activated sludge (RAS) pump station.
2.5.1 Condition and Performance Assessment
2.5.1.1 Junction Box A
Mechanical: Mechanical equipment at Junction Box A included gates. The gates are in acceptable condition. As seen in Figure 6, the hand cranks on the effluent gates are corroded and need to be coated.
Figure 6 Effluent Gates – Corrosion on Hand Cranks
Structural: The structure is in acceptable condition.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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2.5.1.2 Inter-Stage Pump Station
Mechanical: The pumps at the Inter-Stage Pump Station are generally in good condition. Some corrosion was observed on the pumps though. Coating and re-painting the pumps is recommended.
Structural: Overall, structural is in good condition. Minor cracks are present, but these are mostly hairline cracks with no impact to the structure.
Electrical: The overall condition of the electrical equipment is good. Some of the equipment is dirty but there are no visible defects on the enclosures, conduits, and the mounting hardware. City staff have indicated that they have not had any issue with the electrical equipment.
2.5.1.3 Fine Screen Channels
Mechanical: The washer-dewatering-compacting units and booster pumps are in good condition and function well.
Structural: Similar to the Inter-Stage Pump Station, the structural elements are in good condition. Minor cracks are present, but these are mostly hairline cracks with no impact to the structure.
Electrical: The overall condition of the electrical equipment is good. Some of the equipment is dirty but there are no visible defects on the enclosures, conduits, and the mounting hardware. City staff have indicated that they have not had issues with the electrical equipment.
2.5.1.4 Junction Box C
Structural: This structure is in acceptable condition.
2.5.1.5 Flow Distribution Box A
Mechanical: The gates at Flow Distribution Box A are in acceptable condition. The hand cranks have corrosion on them, which should be recoated.
Structural: The structure is in acceptable condition.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-11
Figure 7 Junction Box A
2.5.1.6 Aeration Basins
Mechanical: The submersible mixers in the aeration basins are in good condition. The fine diffusers are generally in acceptable condition, but corrosion was not an issue nor was the piping. Staff indicated that some diffusers had burst though and needed to be replaced. Small diameter piping in the basins is in acceptable condition.
Structural: Aeration Basins Nos. 1-4 are in acceptable condition. Minor cracks and spalls on the rebate at gratings were observed in the field.
Electrical: The overall condition of the electrical equipment is good and acceptable. There is rust on the conduits and mounting hardware for the lighting and receptacles. There are no visible defects on the electrical enclosures, conduits, and mounting hardware. City staff have indicated that they have not had any issues with the electrical equipment.
2.5.1.7 Aeration Blowers
Mechanical: Aeration Blowers No. 1 – 5 were recently replaced in 2017 and are in good condition. No defects were observed.
Electrical: The electrical equipment is in good and acceptable condition. MCC D has some wear but is in acceptable condition. MCC NS and MCC SB have some buckets that are still being used but are mostly decommissioned. Staff have indicated that they do not have current issues with either the mostly decommissioned MCCs or the equipment still in use, considerations should be made in relocating the equipment that is still being used and fully decommissioning the MCCs. Consider including this effort of
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-12
relocating the is use equipment buckets with future upgrades. MCC MD has some wear but is in acceptable condition. MCC GB is dirty but does not have observable defects. It is recommended that MCC GB be cleaned and inspected for any defects. City staff have indicated that they have not had issues with the electrical equipment and with obtaining replacement parts.
2.5.1.8 Aeration Effluent Junction Box D-1 and D-2
Mechanical: The gates in the effluent junction box are in acceptable condition. Some corrosion was observed. It is recommended to coat the hand cranks and gearboxes to protect the equipment.
Structural: Minor corrosion on the gates and hair line cracks on concrete are observed. Overall, the condition of the structure is acceptable.
2.5.1.9 Junction Box D-3 and D-4
Mechanical: Both Junction Box D-3 and D-4 had gates that are in acceptable condition. Some corrosion could be seen as shown in Figure 8. It is recommended that the gearboxes be coated to protect the equipment.
Figure 8 Corrosion on Gearbox
Structural: The junction boxes are in acceptable condition.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
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WATER RECLAMATION FACILITY - FACILITY PLAN 2-13
2.5.1.10 MBR System
Mechanical: The MBR system, membrane equipment, permeate pumps, and backpulse pumps were installed in 2017 and are in good condition. No defects were observed, and City staff did not note any issues with this equipment.
Structural: Corrosion is observed at the brace and gusset connection, and this connection has corroded welds as seen in Figure 9. Periodic inspection is recommended.
Figure 9 Braced Frame near MBR -Corrosion at Brace and Gusset Connection Electrical: The overall condition of the electrical equipment is good. There are no visible defects on the electrical enclosures, conduits, and mounting hardware. City staff have indicated that they have not had issues with the electrical equipment.
2.5.1.11 MBR Blower Building
Mechanical: Along with the MBR system, the equipment in the MBR building was installed in 2017. The scouring and agitation air blowers, air compressors, and air dryers all are in good condition. No defects were observed at the equipment in this building.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-14
Figure 10 Air Scour Blower No. 1
Structural: The existing MBR building is a masonry building built in 2015, which is in good condition. No major cracks or settlement of the structure were observed.
Electrical: The overall condition of the electrical equipment is good. There were no visible defects on the electrical enclosures, conduits, and mounting software. City staff have indicated that they have not had issues with the electrical equipment.
2.5.1.12 Chemical Area
Mechanical: The chemical area contains the sodium hypochlorite and citric acid metering pumps. The pumps worked well and appeared to be in good condition. No defects were observed here.
Structural: The overall structural condition is good. The area was clean with no defects observed in the concrete.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-15
Figure 11 Chemical Area
Electrical: The overall condition of the electrical equipment is in good condition. There were no visible defects on the conduits and mounting hardware. City staff have indicated that they have not had issues with the electrical equipment.
2.5.1.13 RAS Pump Station
Mechanical: The RAS pumps and waste activated sludge (WAS) pumps are in good condition. However, the RAS pumps could be recoated/repainted since sludge is coming out of the air release valve and spilling onto the equipment and surrounding area as seen in Figure 12. It is recommended to install piping from the air release valves to drains instead of having them spill onto the equipment and piping.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-16
Figure 12 RAS Pump – Sludge Spillage
Structural: Overall, structural is in good condition. No major cracks or settlement of the structure were observed.
Electrical: The overall condition of the electrical system is in good condition. There were no visible defects on the electrical enclosures, conduits, and mounting hardware. City staff have indicated they have not had issues with the electrical equipment.
2.5.2 Conclusions and Recommendations
2.5.2.1 Mechanical
Most of the equipment was installed in 2017 and is in good condition. City staff did not mention any issues with the equipment either. The RAS pumps had some sludge spillage coming out from the valve. It is recommended to install piping from the air release valves to drains instead of having them spill onto the equipment and piping. Also, a coating and painting project is recommended for those pumps and the hand cranks on the gates in the junction and flow distribution boxes.
2.5.2.2 Structural
Structures in the secondary treatment area are in good to acceptable condition with little to no defects observed in the field. Multiple structures had minor cracks, which were mostly hairline cracks that had no impact on the structure. The aeration basins also had some minor cracks and spalls on the rebate at
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-17
gratings. In addition, corrosion was observed at the brace and gusset connection near the MBR system.
Periodic inspections are recommended to monitor this development.
2.5.2.3 Electrical
This area is in good condition. Only minor defects, such as rust on some conduits and dirty equipment, were observed in a couple areas, but otherwise, no visible defects were observed. The MCCs in the aeration basin area are in acceptable condition; a few of them, however, are mostly decommissioned. It is recommended to consider relocating the MCCs that are still in use and fully decommissioning those that are mostly decommissioned. This effort should be considered with future upgrades.
2.6 Tertiary Treatment
Tertiary Treatment includes the ultraviolet (UV) equipment and structure, the recycled water distribution box, recycled water equipment, ponds, and the Irrigation Pump Station.
2.6.1 Condition and Performance Assessment
2.6.1.1 UV Area
Mechanical: The channel gates and modules were installed in 2017 and are in good condition. No defects were observed here.
Structural: Overall, the UV effluent box and structure are in good condition. Minor cracks are present and are acceptable as they are hairline/shrinkage cracks. Settlement and movement of structure is not observed.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-18
Figure 13 UV Channels
Electrical: The overall condition of the electrical equipment is good. There were no visible defects on the electrical enclosures, conduits, and mounting hardware. City staff have indicated that they have not had issues with the electrical equipment.
2.6.1.2 Recycled Water Distribution Box
Structural: The Recycled Water Distribution Box is a concrete structure. No major defects are observed.
Minor cracks are present but are acceptable as they are hairline/shrinkage cracks. Settlement and movement of structure is not observed. Overall, the structure is in good condition.
Electrical: The condition of the electrical equipment was good. There were no visible defects on the electrical enclosures, conduits, and mounting hardware. City staff have indicated that they have not had issues with the electrical equipment.
2.6.1.3 Recycled Water Equipment
Mechanical: Equipment included in this area is the hydropneumatics recycled water tank, plant water pumps, and an air compressor. All of these were installed in 2017 and are in good condition. The plant water pumps could use a touch up paint job though.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-19
Figure 14 Plant Water Pumps
Electrical: The condition of the electrical equipment is good. There were no visible defects on the electrical enclosures, conduits, and mounting hardware. City staff have indicated that they have not had issues with the electrical equipment.
2.6.1.4 Regulating Ponds A and B
Mechanical: The regulating ponds are in good condition. No defects were observed during the site visit.
2.6.1.5 Ponds 2 and 3
Mechanical: City staff indicated that these ponds are in good condition, and they do not have any issues with them.
2.6.1.6 Irrigation Pump Station
Mechanical: Based on City feedback, the pumps at the Irrigation Pump Station are in good condition.
These pumps were installed in 2017, and City staff indicated that they run properly and do not have issues.
Structural: According to City staff, the Irrigation Pump Station wet well, which was constructed in 2017, is in good condition.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-20
2.6.2 Conclusions and Recommendations
2.6.2.1 Mechanical
The majority of this area was installed in 2017. All the equipment is in good condition, and no defects were observed. No action is required for the mechanical equipment here.
2.6.2.2 Structural
The structures in this area are in good condition with little to no defects found in the structures. No action is required for the structures here.
2.6.2.3 Electrical
Electrical equipment in this area is in good condition with no visible defects on the enclosures, conduits, and mounting hardware. No action is required for the electrical equipment.
2.7 Solids Handling
This section includes the thickening system (gravity belt thickeners [GBTs] and associated equipment and thickened WAS [TWAS]), sludge disintegration system, digesters and associated equipment, digester gas treatment system, and sludge dewatering equipment.
2.7.1 Condition and Performance Assessment
2.7.1.1 Thickening System
Mechanical: The GBTs and TWAS pumps are in acceptable condition with minor defects. The TWAS pump piping could be coated. The wash water booster pumps and polymer system are in fair condition.
Corrosion was noted on the booster pump, which would benefit from a coating job.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-21
Figure 15 Wash Water Booster Pump
Structural: Overall, the structure is in good condition. Hairline cracks observed are not detrimental to the adequacy of the pad.
Electrical: The overall condition of the electrical equipment is in good and acceptable condition. There were no visible defects on the electrical enclosures, conduits, and mounting hardware. City staff have not indicated any issues with the equipment.
2.7.1.2 Digester Area
Mechanical: Generally, the digester equipment is in acceptable condition except for Boiler No. 3 being in fair condition. Boiler No. 3 had significant corrosion and defects on the piping. Also, the valves on Digester No. 7 need to be painted. Sludge Transfer Pump Station No. 1 and the Digester No. 8 equipment, installed in 2017, are in good condition. Digester No. 4 was out of service when the condition assessment was conducted.
Structural: Overall, Digesters No. 1 – 7 are in acceptable condition. Minor cracks are present but are acceptable as they are hairline/shrinkage cracks. Settlement and movement of the structures is not observed.
Electrical: The overall condition of the electrical equipment is in good and acceptable condition. Even though city staff have not had issues with MCC BC, consideration should be taken into replacing the MCC as it will become harder to find replacement parts. There are no visible defects on the other electrical enclosures, conduits, and mounting hardware.
2.7.1.3 Gas Treatment System
Mechanical: The gas treatment system was installed in 2017 and is in good condition. No defects were observed.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-22
Structural: Overall, structural is in good condition.
Electrical: The overall condition of the electrical system is in good condition. There are no visible defects on the electrical enclosures, conduits, and mounting hardware. City staff have indicated that they have not had issues with the electrical equipment.
2.7.1.4 Sludge Dewatering
Mechanical: The dewatering equipment, installed in 2017, is in good to acceptable condition. Struvite buildup was present on one of the screw presses, so it was taken offline for maintenance, leaving only one screw press running. Both screw presses also had bulging at the panels. Additionally, staff noted that when high loads come into the plant, both screw presses need to run at full capacity to handle the influent. A third screw press should be considered to provide redundancy in the system. Coating the motors and gearboxes of the screw presses should be considered as well.
Figure 16 Struvite Formation on the Screw Press
Structural: Overall, the structure supporting the screw presses is in acceptable condition. There appears to be no significant settlement of columns/foundations. The sludge drying beds also are in good condition.
Electrical: The overall condition of the electrical equipment is in good condition. There are no visible defects on the electrical enclosures, conduits, and mounting hardware. City staff have indicated that they have not had issues with the electrical equipment.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 2-23
Site/Civil: The drainage in this area is in poor condition. City staff noted that the permeate piping periodically overflows from the screen manhole under the screw presses, which should be addressed. See Figure 17 for location of occasional overflow.
Figure 17 Screen Manhole Under Screw Presses – Location of Overflows
2.7.2 Conclusions and Recommendations
2.7.2.1 Mechanical
Overall, this area is in acceptable condition. In several areas, corrosion was observed as well as equipment needing touch-up paint. It is recommended to have a coating and painting project to address these defects. For the screw presses, City staff noted that both screw presses at full capacity when loading is high to the plant, which means a redundant screw press is not available. It is recommended to add a third screw press in the near future.
2.7.2.2 Structural
There are no major issues, and overall conditions of the structures are in good condition. Minor defects or places of repair have been identified in this report and are documented in the above sections.
2.7.2.3 Electrical
This area is in good condition and no action is required for the equipment here.
TECHNICAL MEMORANDUM 2 – CONDITION ASSESSMENT
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN
APPENDIX A CONDITION ASSESSMENT SUMMARY TABLE
Asset Process Sub-Process Discipline Asset Class Approxi mate Year Built Approximate Structure Age Estimated Useful Life POF/ Condition Reinvestment Year South Diversion Structure Preliminary
Treatment Headworks Structural Structure 2002 21 50 5 2023 Influent Gates Preliminary
Treatment Headworks Mechanical Slide Gate 2002 21 20 3 2023 Headworks No. 1 Preliminary
Treatment Headworks Structural Building 2002 21 50 2 2053 Bar Screens No. 1 and 2 Preliminary
Treatment Headworks Mechanical Screen 2002 21 15 3 2023 Washer Compactor Preliminary
Treatment Headworks Mechanical Compactor 2002 21 15 3 2023 Influent Pumps No. 1-5 Preliminary
Treatment Headworks Mechanical Pump 2002 21 20 2 2023
Influent Pump No. 6 Preliminary
Treatment Headworks Mechanical Pump 2017 6 20 1 2037
Grit Basins Preliminary
Treatment Grit Removal Structural Structure 2002 21 50 2 2053 Grit Basins Preliminary
Treatment Grit Removal Mechanical Basin 2002 21 50 3 2040 Gates Preliminary
Treatment Grit Removal Mechanical Slide Gate 2002 21 20 3 2030 Grit Pumps Preliminary
Treatment Grit Removal Mechanical Pump 2002 21 20 3 2023 Grit Classifiers Preliminary
Treatment Grit Removal Mechanical Classifier 2002 21 20 3 2023 Biofilter Fan No. 1 and 2 Preliminary
Treatment Biofilter Mechanical Fan 2017 6 15 1 2032
Biofilter Cells Preliminary
Treatment Biofilter Mechanical Media 2017 6 10 1 2027
Septage Receiving Station Preliminary
Treatment
Septage Receiving
Station Structural Structure 2017 6 50 2 2067
Motor Control Center (2 12KV Switch
Gears)
Preliminary
Treatment N/A Electrical MCC 2017 6 30 1 2047
Motor Control Center "H" Preliminary
Treatment Headworks Electrical MCC 1966 57 30 2 2023
Motor Control Center "BIO" Preliminary
Treatment Biofilter Electrical MCC 2017 6 30 2 2041
Bar Screens 1 & 2 Local Control
Station
Preliminary
Treatment Headworks Electrical Panel 2002 21 20 1 2023
Grit Pumps (4) Local Control Stations Preliminary
Treatment Grit Removal Electrical Panel 2002 21 20 2 2023 12 kVA Switch Gear Preliminary
Treatment N/A Electrical Switchgear 2017 6 30 1 2047
Lighting Panel H Preliminary
Treatment Headworks Electrical Panel 2002 21 20 2 2023
Lighting Transformer "H" Preliminary
Treatment Headworks Electrical Transformer/Lighting 2002 21 20 2 202 3 Raw Sewage Pump VFD Cabinets Preliminary
Treatment Headworks Electrical VFD 2002 21 15 1 2023
Flow Split Structure Primary Treatment Headworks Struc tural Structure 1966 57 50 1 2073 Primary Distribution Box A Primary Treatment
Primary
Sedimentation Basin
1, 2, and 3
Structural Structure 1966 57 50 2 2053
Primary Distribution Box B Primary Treatment
Primary
Sedimentation Basin
1, 2, and 3
Structural Structure 1992 31 50 2 2053
A - 1
Asset Process Sub-Process Discipline Asset Class Approxi mate Year Built Approximate Structure Age Estimated Useful Life POF/ Condition Reinvestment Year Primary Sedimentation Basin 1, 2, 3 Primary Treatmen t
Primary
Sedimentation Basin
1, 2, and 3
Structural Structure 1966 57 50 2 2053
Sludge Collectors Primary Treatment
Primary
Sedimentation Basin
1 Mechanical Chain and Flight 2023 0 30 0 2053
Scum Skimmers Primary Treatment
Primary
Sedimentation Basin
1 Mechanical Skimmer 2023 0 20 0 2043
Sludge Collectors Primary Treatment
Primary
Sedimentation Basin
2 Mechanical Chain and Flight 2004 19 30 2 2034
Scum Skimmers Primary Treatment
Primary
Sedimentation Basin
2 Mechanical Skimmer 2004 19 20 2 2024
Sludge Collectors Primary Treatment
Primary
Sedimentation Basin
3 Mechanical Chain and Flight 2007 16 30 2 2037
Scum Skimmers Primary Treatment
Primary
Sedimentation Basin
3 Mechanical Skimmer 2007 16 20 2 2027
Effluent Troughs Primary Treatment
Primary
Sedimentation Basin
1, 2, and 3
Mechanical Trough 1966 57 20 3 2023
Primary Sedimentation Basin 4 Primary Treatment
Primary
Sedimentation Basin
4 Structural Structure 1992 31 50 2 2053
Sludge Collectors Primary Treatment
Primary
Sedimentation Basin
4 Mechanical Chain and Flight 2014 9 30 2 2041
Scum Skimmers Primary Treatment
Primary
Sedimentation Basin
4 Mechanical Skimmer 1992 31 20 3 2023
Effluent Troughs Primary Treatment
Primary
Sedimentation Basin
4 Mechanical Trough 1992 31 20 3 2023
Primary Sedimentation Basin 5 Primary Treatment
Primary
Sedimentation Basin
5 Structural Structure 2001 22 50 2 2053
Sludge Collectors Primary Treatment
Primary
Sedimentation Basin
5 Mechanical Chain and Flight 2001 22 30 2 2031
Scum Skimmers Primary Treatment
Primary
Sedimentation Basin
5 Mechanical Skimmer 2001 22 20 3 2023
Effluent Troughs Primary Treatment
Primary
Sedimentation Basin
5 Mechanical Trough 2001 22 20 2 2023
Primary Sludge Grinders (2) Primary Treatment
Primary
Sedimentation Mechanical Grinder 2017 6 15 3 2028
Primary Sludge Pumps (4) Primary Treatment
Primary
Sedimentation Mechanical Pump 2017 6 20 2 2035
Scum Grinder Primary Treatment Scum Box No. 1 Mechanic al Grinder 1966 57 15 4 2023 Scum Pump Primary Treatment Scum Box No. 1 Mechanical P ump 1966 57 20 4 2023 Scum Grinder Primary Treatment Scum Box No. 2 Mechanic al Grinder 1992 31 15 3 2023 Scum Pump Primary Treatment Scum Box No. 2 Mechanical P ump 1992 31 20 3 2023 Effluent Gates Primary Treatment Junction box Mechanic al Slide Gate 1966 57 20 3 2023 A - 2
Asset Process Sub-Process Discipline Asset Class Approxi mate Year Built Approximate Structure Age Estimated Useful Life POF/ Condition Reinvestment Year Motor Control Center "6000" Primary Treatment Primary
Sedimentation Electrical MCC 2017 6 30 1 2047
Primary Sludge Pump Local Control
Stations (4) Primary Treatment
Primary
Sedimentation Electrical Panel 2017 6 20 1 2037
Primary Sludge Grinders Control
Panels Primary Treatment
Primary
Sedimentation Electrical Panel 2017 6 20 1 2037
Junction Box A Secondary
Treatment Junction box Structural Structure 1966 57 50 2 2053 Vertical Axial Flow Propeller Pumps (3) Secondary
Treatment
Inter-Stage Pump
Station Mechanical Pump 2017 6 20 2 2035
Washing-Dewatering-Compacting
Unit
Secondary
Treatment Fine Screen Channels Mechanical Compactor 2017 6 15 1 2032 Booster Pump Secondary
Treatment Fine Screen Channels Mechanical Pump 2017 6 20 1 2037 Junction Box C Secondary
Treatment Fine Screen Channels Structural Structure 1975 48 50 2 205 3 Flow Distribution Box A Secondary
Treatment Aeration Basins Structural Structure 1975 48 50 2 2053 Aeration Basin 1, 2, 3, and 4 Secondary
Treatment
Aeration Basin 1, 2,
3, and 4 Structural Basin 1966 57 50 2 2053
Submersible Mixers Secondary
Treatment
Aeration Basin 1, 2,
3, and 4 Mechanical Mixer 2017 6 20 1 2037
Fine Bubble Diffusers Secondary
Treatment
Aeration Basin 1, 2,
3, and 4 Mechanical Diffuser 2017 6 15 2 2032
Small Diameter Piping Secondary
Treatment
Aeration Basin 1, 2,
3, and 4 Mechanical Pipe 2017 6 40 2 2047
Aeration Blower No. 1-5 Secondary
Treatment
Blower Building No.
1 Mechanical Blower 2017 6 30 1 2047
Aeration Effluent Junction Box D-1 Secondary
Treatment
Aeration Basin 1, 2,
3, and 4 Structural Structure 1975 48 50 2 2053
Junction Box D-3 Secondary
Treatment
Aeration Basin 1, 2,
3, and 4 Structural Structure 2015 8 50 2 2065
Aeration Effluent Junction Box D-2 Secondary
Treatment
Aeration Basin 1, 2,
3, and 4 Structural Structure 2015 8 50 2 2065
Junction Box D-4 Secondary
Treatment
Aeration Basin 1, 2,
3, and 4 Structural Structure 2015 8 50 2 2065
Membrane Equipment Secondary
Treatment
Membrane
Bioreactor System Mechanical Equipment 2017 6 20 1 2037 Permeate Pumps Secondary
Treatment
Membrane
Bioreactor System Mechanical Pump 2017 6 20 1 2037
Backpulse Pumps Secondary
Treatment
Membrane
Bioreactor System Mechanical Pump 2017 6 20 1 2037
MBR Blower Building Secondary
Treatment MBR Blower Building Structural Building 2015 8 50 1 2073 Scouring Blowers (4) Secondary
Treatment MBR Blower Building Mechanical Blower 2017 6 30 1 2047 Agitation Air Blowers (2) Secondary
Treatment MBR Blower Building Mechanical Blower 2017 6 30 1 2047 Air Compressors (2) Secondary
Treatment MBR Blower Building Mechanical Compressor 2017 6 15 1 2032 Air Dryer (2) Secondary
Treatment MBR Blower Building Mechanical Air Dryer 2017 6 20 1 2037 Sodium Hypochlorite Metering Pump Secondary
Treatment Chemical Area Mechanical Pump 2017 6 20 1 2037 Citric Acid Metering Pump Secondary
Treatment Chemical Area Mechanical Chemical Pump 2017 6 10 1 2027 A - 3
Asset Process Sub-Process Discipline Asset Class Approxi mate Year Built Approximate Structure Age Estimated Useful Life POF/ Condition Reinvestment Year Sodium Hypochlorite Spray Nozzles Secondary
Treatment Chemical Area Mechanical Nozzle 2017 6 15 2 2032 RAS Pumps (4) Secondary
Treatment RAS Pump Station Mechanical Pump 2017 6 20 1 2037 WAS Pumps (2) Secondary
Treatment RAS Pump Station Mechanical Pump 2017 6 20 1 2037 Standby Generators 1 Secondary
Treatment N/A Electrical Generator 2017 6 30 1 2047
Standby Generators 2 Secondary
Treatment N/A Electrical Generator 2017 6 30 1 2047
Blower Bldg 1 XFMR Secondary
Treatment MBR Blower Building Electrical Transformer/Lighting 20 17 6 20 1 2037 Blower Bldg 2 XFMR Secondary
Treatment MBR Blower Building Electrical Transformer/Lighting 20 17 6 20 1 2037 MCC-SB Secondary
Treatment
Blower Building No.
1 Electrical MCC 1970 53 30 4 2023
MCC-NS Secondary
Treatment
Blower Building No.
1 Electrical MCC 1970 53 30 4 2023
Inter-Stage Pump VFD Panels Secondary
Treatment
Inter-Stage Pump
Station Electrical VFD 2017 6 15 1 2032
Power Panel "5PP-01" Secondary
Treatment MBR Blower Building Electrical Panel 2017 6 20 1 2037 Switchboard 5000 Secondary
Treatment MBR Blower Building Electrical Switchgear 2017 6 30 1 2047 MBR Control Panels Secondary
Treatment
Membrane
Bioreactor System Electrical Panel 2017 6 20 1 2037
Motor Control Center "Recycle" Secondary
Treatment Recycled water Electrical MCC 2017 6 30 3 2033 Switchboard 4000 Secondary
Treatment
Blower Building No.
1 Electrical Switchgear 2017 6 30 1 2047
Motor Control Center "3000" Secondary
Treatment
Blower Building No.
1 Electrical MCC 2017 6 30 1 2047
Lighting Panel 4LP-1 Secondary
Treatment
Blower Building No.
1 Electrical Transformer/Lighting 2017 6 20 1 2037
Motor Control Center "MBR" Secondary
Treatment
Membrane
Bioreactor System Electrical MCC 2017 6 30 1 2047
Permeate Pump VFD Panel (10) Secondary
Treatment
Membrane
Bioreactor System Electrical VFD 2017 6 15 1 2032
Backpulse Pump VFD Cabinets 1 & 2 Secondary
Treatment
Membrane
Bioreactor System Electrical VFD 2017 6 15 1 2032
RAS Pump VFD Cabinets (1-4) Secondary
Treatment RAS Pump Station Electrical VFD 2017 6 15 1 2032 Blower Building 1 Power Panels Secondary
Treatment
Blower Building No.
1 Electrical Panel 2017 6 20 1 2037
Transformer E Secondary
Treatment MBR Blower Building Electrical Transformer/Liquid Fil led 2017 6 30 1 2047 Fine Screen Control Panels Secondary
Treatment Fine Screen Channels Electrical Panel 2017 6 20 2 2035 Motor Control Center "MD" Secondary
Treatment
Blower Building No.
1 Electrical MCC 1992 31 30 2 2023
Motor Control Center "D" Secondary
Treatment
Blower Building No.
1 Electrical MCC 1995 28 30 2 2025
Gravity Belt Thickener Solids Handling Thickening Mech anical Thickener 1992 31 20 3 2023 GBT Wash Water Booster Water
Pumps Solids Handling Thickening Mechanical Pump 1992 31 20 3 202 3 Thickened WAS Pumps (2) Solids Handling Thickening Mec hanical Pump 1992 31 20 2 2023 Polymer Injection Solids Handling Thickening Mechanica l Injector 1992 31 15 3 2023 A - 4
Asset Process Sub-Process Discipline Asset Class Approxi mate Year Built Approximate Structure Age Estimated Useful Life POF/ Condition Reinvestment Year Digester No. 1-4 Sludge Pumps Solids Handling Digesti on Mechanical Pump 2017 6 20 2 2035 Dig 1-4 Heating Equipment Solids Handling Digestion Me chanical Heat Exchanger Unknown Unknown 20 2 2035 Digester 1, 2, 3, and 4 Mixing
Equipment Solids Handling Digestion Mechanical Pump 2017 6 20 2 2035 Digester 5 Heating Equipment Solids Handling Digestio n Mechanical Pump Unknown Unknown 20 2 2035 Digester 5 Mixing Equipment Solids Handling Digestion Mechanical Pump 2017 6 20 2 2035 Digester 6 Heating Equipment Solids Handling Digestio n Mechanical Pump Unknown Unknown 20 2 2035 Digester 6 Mixing Equipment Solids Handling Digestion Mechanical Pump 2017 6 20 2 2035 Digester 7 Heating Equipment Solids Handling Digestio n Mechanical Pump Unknown Unknown 20 2 2035 Digester 7 Mixing Equipment Solids Handling Digestion Mechanical Pump 2017 6 20 2 2035 Sludge Transfer Pump Station No.1
Pump Solids Handling Sludge Transfer
Pump Station Mechanical Pump 2017 6 20 1 2037
Digester 8 Heating Equipment Solids Handling Digestio n Mechanical Pump 2017 6 20 1 2037 Digester 8 Mixing Equipment Solids Handling Digestion Mechanical Pump 2017 6 20 1 2037 Boilers #1 and #2 Solids Handling Digestion Mechanical Bo iler 2011 12 20 2 2031 Boiler #3 Solids Handling Digestion Mechanical Boiler 199 8 25 20 3 2023 Digester Gas Booster Blowers Solids Handling Digestio n Mechanical Blower 2017 6 30 1 2047 Digester Sludge Dewatering Feed
Pumps (3) Solids Handling Dewatering Mechanical Pump 2017 6 20 1 2037 Sludge Dewatering Building Solids Handling Dewatering Mechanical Building 2017 6 50 1 2067 Screw Presses (2) Solids Handling Dewatering Mechanica l Screw Press 2017 6 20 2 2035 Screw Presses Solids Handling Dewatering Site/Civil Pip e 2017 6 40 4 2031 Digester Gas Holder Solids Handling Gas Treatment Mech anical Tank 2017 6 30 1 2047 Gas Treatment System Solids Handling Gas Treatment Mec hanical Gas Treatment 2017 6 20 1 2037 IC Engine Solids Handling Gas Treatment Mechanical Icengine 2017 6 20 1 2037 Waste Gas Flare Solids Handling Gas Treatment Mechanic al Flare 2017 6 15 1 2032 MCC-RPGS Solids Handling Gas Treatment Electrical MCC 20 17 6 30 1 2047 Motor Control Center "BC" Solids Handling Digestion Electrical MCC 1975 48 30 2 2023 Motor Control Center "BC1" Solids Handling Digestion Electrical MCC 2017 6 30 1 2047 Motor Control Center "DW" Solids Handling Dewatering Electrical MCC 2017 6 30 1 2047 Polymer Control Panels Solids Handling Dewatering Electrical Panel 2017 6 20 1 2037 Screw Press Control Panel Solids Handling Dewatering Electrical Panel 2017 6 20 1 2037 Sludge Drying Beds Solids Handling Dewatering Structur al Drying Bed 1992 31 50 1 2073 Motor Control Center "BA" Solids Handling Digestion Electrical MCC 2017 6 30 1 2047 Gravity Belt Thickener Remote Control
Panels 1 & 2 Solids Handling Thickening Electrical Panel 1992 31 20 1 2023 Lighting Panel LP & Transformer Solids Handling
Thickening Electrical Transformer/Lighting 1992 31 20 1 2023 Dewatering Screw Press Disconnects 1
& 2 Solids Handling Dewatering Electrical Disconnect 2017 6 20 1 2037 Digester Sludge Grinder Control
Panels Solids Handling Digestion Electrical Panel 2017 6 20 1 2037 7LP-01 MPZ Panel Solids Handling
Dewatering Electrical Transformer/Lighting 2017 6 20 2 2035 Digester Gas Holder Unit Control
Panel Solids Handling Gas Treatment Electrical Panel 2017 6 20 1 2037 Motor Control Center "A" Solids Handling
Gas Treatment Electrical MCC 2017 6 30 1 2047
Motor Control Center "GB" Solids Handling Thickening Electrical MCC 1992 31 30 1 2023 Power Command Transfer Switch Solids Handling Digestion Electrical Transfer Switch 1992 31 30 3 2023 Gravity Belt Thickener Local Control
Panels 1 & 2 Solids Handling Thickening Electrical Panel 1992 31 20 1 2023 Sludge Transfer Pump Station
Electrical Equipment Solids Handling
Sludge Transfer
Pump Station Electrical Panel 2017 6 20 1 2037
Digester 8 Solids Handling Digestion Electrical Panel 2017 6 20 1 2037 Digester 7 Solids Handling Digestion Structural Structure 2001 22 50 2 2053 Digester 8 Solids Handling Digestion Structural Structure 2017 6 50 2 2067 Gravity Belt Thickener Solids Handling Thickening Structural Structure 1992 31 50 1 2073 Digester 6 Solids Handling Digestion Structural Structure 1998 25 50 2 2053 Digester 1, 2, 3, 4, & 5 Solids Handling Digestion Structural Structure 1966 57 50 2 2053 A - 5
Asset Process Sub-Process Discipline Asset Class Approxi mate Year Built Approximate Structure Age Estimated Useful Life POF/ Condition Reinvestment Year UV Channel Gates Tertiary Treatment UV area Mechanical Slide Gate 2017 6 20 1 2037 UV Modules Tertiary Treatment UV area Mechanical UV Sys tem 2017 6 20 1 2037 UV Effluent Box Tertiary Treatment UV area Structural S tructure 2017 6 50 1 2073 Regulating Pond A & B Tertiary Treatment Regulating R eservoir Mechanical Pond 2017 6 50 1 2067 Pond 2 & 3 Tertiary Treatment Pond Mechanical Pond 1996 2 7 50 1 2046 Wet well Tertiary Treatment Irrigation Pump
Station Structural Structure 2017 6 50 1 2073
Pumps Tertiary Treatment Irrigation Pump
Station Mechanical Pump 2017 6 20 1 2037
RW Distribution Box Tertiary Treatment Recycled water Structural Structure 2017 6 50 1 2073 Hydropneumatic RW Tank Tertiary Treatment Recycled wa ter Mechanical Tank 2017 6 30 1 2047 Hydropneumatic RW Tank Tertiary Treatment Recycled wa ter Mechanical Pump 2017 6 20 1 2037 Air Compressor Tertiary Treatment Recycled water Mecha nical Compressor 2017 6 15 1 2032 UV Channels 1 & 2 Panels Tertiary Treatment UV area Electrical Panel 2017 6 20 1 2037 Well and Expansion Tank Other N/A Mechanical Tank 2003 20 30 2 2033 A - 6
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 3
Environmental Opportunities
FINAL / February 2024
Water Reclamation Facility – Facility Plan
TECHNICAL MEMORANDUM 3
Environmental Opportunities
FINAL / February 2024
This document is released for the purpose of information exchange review and planning only under the authority of Christine Polo, February 2024, CA PE 6843.
TECHNICAL MEMORANDUM 3 – ENVIRONMENTAL OPPORTUNITIES
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN i
Contents
TM 3 ENVIRONMENTAL OPPORTUNITIES 3-1
3.1 Introduction 3-1
3.2 Recycled Water Opportunities 3-1
3.3 Class A Biosolids Opportunities 3-1
3.3.1 Introduction 3-1
3.3.2 Current Solids Processes and Biosolids Management Practices 3-1
3.3.3 Regulatory Drivers 3-2
3.3.4 Financial Drivers 3-3
3.3.5 Class A Options and High-Level Cost Estimates 3-4
3.3.6 Recommendations 3-6
3.4 Energy Opportunities 3-7
3.4.1 Introduction 3-7
3.4.2 Current Digester Gas Utilization and Energy Generation Systems 3-7
3.4.3 Regulatory and Financial Drivers 3-7
3.4.4 Energy Opportunities and High-Level Cost Estimates 3-9
3.4.5 Recommendations 3-11
Tables
Table 1 Biosolids Hauling and Land Application Rates and Quantities 3-3 Table 2 Class A Treatment Technology Options, Advantages and Disadvantages, and High-Level Cost Estimates 3-4
Table 3 Projected Future Air-Dried Solids Hauling and Land Application Costs for Realistic and Worst-Case Scenario 3-6
Figures
Figure 1 County Land Application Ordinances in California 3-2 Figure 3 Digester Gas Utilization Options 3-9
TECHNICAL MEMORANDUM 3 – ENVIRONMENTAL OPPORTUNITIES
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Abbreviations
AACE Association for the Advancement of Cost Engineering ACF Advanced Clean Fleets
AWDF average dry weather flow
BMP biosolids master plan
C Celsius
Carollo Carollo Engineers
CASA California Association of Sanitation Agencies
CHP combined heat and power
CIP capital improvement program
City City of Visalia
CPUC California Public Utilities Commission
eRIN electric renewable identification number
F Fahrenheit
FOG fats, oils, and grease
HRT hydraulic retention time
H2S hydrogen sulfide
IRA Inflation Reduction Act
KOH potassium hydroxide
kW kilowatts
kWh/year kilowatt-hours per year
LCFS Low Carbon Fuel Standard
M million
MG million gallons
mgd million gallons per day
MW megawatts
NaOH sodium hydroxide
O&M operations and maintenance
PFAS per- and polyfluoroalkyl substances
PSRP Process to Significantly Reduce Pathogens
R-CNG renewable compressed natural gas
RFS Renewable Fuel Standard
RIN renewable identification number
RNG renewable natural gas
scfd standard cubic feet per day
scfm standard cubic feet per minute
SGIP Self-Generation Incentive Program
SWRCB California State Water Resources Control Board
TM technical memorandum
TECHNICAL MEMORANDUM 3 – ENVIRONMENTAL OPPORTUNITIES
FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN iii
TPAD temperature based anaerobic digestion
USEPA United States Environmental Protection Agency
W watt
WT wet US tons
WRF Water Reclamation Facility
WWTP wastewater treatment plant
ZEV zero emission vehicle
TECHNICAL MEMORANDUM 3 – ENVIRONMENTAL OPPORTUNITIES
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CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 3-1
TM 3 ENVIRONMENTAL OPPORTUNITIES
3.1 Introduction
This technical memorandum (TM) presents the findings of the evaluation of environmental opportunities performed for the City of Visalia’s (City) Water Reclamation Facility (WRF). The evaluation includes potential environmental project options to include in the Near-Term and Long-Term capital improvement programs (CIPs), including:
▪ Recycled water opportunities.
▪ Class A biosolids opportunities.
▪ Energy opportunities.
3.2 Recycled Water Opportunities
Originally, recycled water opportunities were going to be investigated as part of this TM. However, after talking to City staff, these efforts were shifted to focus more on evaluating biosolids and energy opportunities.
3.3 Class A Biosolids Opportunities
3.3.1 Introduction
The City is interested in investigating Class A treatment and end-use options due to increasing costs for biosolids management and regulatory drivers.
3.3.2 Current Solids Processes and Biosolids Management Practices The WRF processes primary solids and thickened waste activated sludge in anaerobic digesters. The digested biosolids are then dewatered in screw presses and dried in drying beds. Based on the 2020 to 2023 data, typical solids concentrations are 16 percent total solids (TS) for the dewatered biosolids and 81 to 90 percent TS for the dried biosolids. After drying, the solids are stored in a stockpile. The City either contracts with a third party, Denali, for hauling and beneficial use of the dried biosolids via bulk agricultural land application in Merced and Madera counties or uses its biosolids as landfill alternative cover.
40 CFR Part 503, the United States Environmental Protection Agency (USEPA) regulation that governs biosolids management, classifies air drying as a Process to Significantly Reduce Pathogens (PSRP), which produces Class B biosolids. To produce Class B biosolids using air drying, the following conditions must be met:
▪ To achieve the pathogen reduction requirement, solids must be dried for a minimum of three months with the average daily ambient temperature above 0C (32F) for two of the three months. ▪ To achieve the vector attraction reduction requirement, digested solids must be dried to at least 75 percent TS and undigested solids must be dried to at least 90 percent TS.
TECHNICAL MEMORANDUM 3 – ENVIRONMENTAL OPPORTUNITIES
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Some air-drying facilities in California obtain Class A designation by conducting ongoing testing of fecal pathogens. The City tested their dried biosolids stockpiles in 2021 and 2022 for pathogens and found that the pathogen concentrations met the limits required to be classified as Class A.
3.3.3 Regulatory Drivers
A detailed review of current and expected future regulations will be covered in a separate master plan.
However, this section provides a high-level overview of two major regulatory drivers that could impact biosolids management and may warrant an evaluation of Class A options.
Class B land application is banned in Tulare county, where the City is located, as well as most of the surrounding counties, including Fresno, Kings, Kern, and San Luis Obispo, as shown in Figure 1. This leads to long hauling distances and correspondingly costly hauling rates since Class B biosolids need to be hauled to far-away counties for beneficial use.
Figure 1 County Land Application Ordinances in California Expected future federal and state-level limits on per- and polyfluoroalkyl substances (PFAS) may hinder biosolids land application:
▪ USEPA is conducting a risk assessment and may establish limits by 2025/2026. ▪ California State Water Resources Control Board (SWRCB) recently issued an order (WQ 2020-0015- DWQ) that requires wastewater treatment plants with average dry weather flow (AWDF) over 5 million Visalia
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gallons per day (mgd) to sample 31 PFAS analytes in biosolids starting March 2023. Limits may be set based on findings from SWRCB sampling and analysis.
▪ If stringent PFAS concentration limits are established for biosolids, this could drive wastewater agencies to either landfill biosolids or implement emerging and possibly thermal technologies, such as gasification and pyrolysis (if proven to remove PFAS compounds).
3.3.4 Financial Drivers
Like many other wastewater agencies in the region, the City has experienced rapidly increasing third -party hauling and land application rates. Table 1 shows the historical rates and biosolids quantities in wet US tons (WT) from 2014 to 2022. As seen in this table, rates almost doubled in 2022.
Table 1 Biosolids Hauling and Land Application Rates and Quantities Year Hauling Dates Quantity (WT) Rate ($/WT) Cost ($)
2014 9/2/2014-11/25/2014 2,668 $28.16 $75,136
2015 Data not available.
2016 Data not available.
2017 11/6/2017-
11/24/2017
1,419 $33.50 $47,542
2018 8/27/2018-8/31/2018 1,949 $33.50 $65,280
2019 11/7/2019-
11/13/2019
1,906 $35.45 $67,567
2020 8/12/2020-8/14/2020 2,313 $36.45 $84,314
2021 Data not available.
2022(1) 1/23/2023-1/31/2023 3,089 $72 $70,603 for the 20 percent TS batch. No invoice provided for the 88 percent TS batch.
Notes:
(1) The 2022 biosolids included two batches: one consisting of 932 WT at 20 percent TS and one consisting of 3,089 WT at 88 percent TS. The wet batch was likely due to rain re-wetting a portion of the biosolids stockpile.
When evaluating solids treatment alternatives, costs for necessary expansions and upgrades for continued operations of the existing facilities need to be accounted for. A capacity analysis of existing processes described in TM 1 – Near-Term Process Performance Evaluation identified the following solids process capacity limitations.
▪ Anaerobic Digestion: An additional anaerobic digester will need to be constructed by 2027 to meet the 15-day hydraulic residence time (HRT) requirement. The capital cost of a new digester and all its required ancillary equipment is estimated at $43 Million (M). ▪ Dewatering: A third screw press is needed to have sufficient firm capacity and redundancy for the current flows and loads. The capital cost for installing a third screw press and all its ancillary equipment is estimated at $5M.
For more details on the anaerobic digestion and dewatering expansion projects, see TM 4 – Near-Term Project Descriptions and TM 5 – Near-Term Capital Improvement Program, which provide project descriptions and CIP cost estimates, respectively.
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3.3.5 Class A Options and High-Level Cost Estimates
The most viable option for the City to produce a Class A product would be to obtain Class A designation for their air dried biosolids by conducting ongoing testing of fecal pathogens. Initial testing of pathogens indicates that this is possible.
Table 2 summarizes additional treatment technologies that the City could use to achieve Class A biosolids, as well as high-level capital cost estimates. The cost estimates were prepared in accordance with the guidelines of the Association for the Advancement of Cost Engineering (AACE) for a Class 5 estimate, with an expected accuracy range of -30 to +50 percent. These costs are provided below to give the City a rough estimate of what a new Class A solids treatment process may cost. However, it is important to note that factors such as solids quantities and characteristics, usable existing infrastructure, and desig n requirements and preferences vary for each specific wastewater agency and wastewater treatment plant (WWTP). Furthermore, scaling costs from one agency to another and from larger to smaller capacity, and projecting costs over four years is expected to further widen the accuracy range.
Table 2 Class A Treatment Technology Options, Advantages and Disadvantages, and High-Level Cost Estimates Class A
Technology General Description Advantages Disadvantages Capital Cost Estimate
Thermal
Hydrolysis
Process
(THP)
Pre-digestion thermal
hydrolysis uses high heat
and high pressure to
stabilize sludge prior to
anaerobic digestion.
▪ Reduces required
anaerobic digestion
volume.
▪ Higher volatile solids
reduction and digester
production.
▪ Increases
dewaterability.
▪ Highly complex process requiring
sludge screening, pre-dewatering
centrifuges, steam boiler and
steam supply system, and high-
heat and high-pressure tanks.
▪ Steam system requires a full-time
certified steam boiler operator.
▪ High ammonia load in recycle
stream.
▪ No expected reduction of PFAS.
$23 Million
Batch
Temperature
Phased
Anaerobic
Digestion
(TPAD)
Batch TPAD involves a
thermophilic continuous
phase, followed by a bath
thermophilic phase, and a
mesophilic continuous
phase.
▪ Higher volatile solids
reduction and digester
production.
▪ May increase
digestion capacity
since higher volatile
solids loading rate is
possible.
▪ Staged digestion, batch phase,
and heating and cooling equipment
add process and operational
complexity.
▪ High ammonia load in recycle
stream.
▪ No expected reduction of PFAS.
Highly
variable. $10
to $40
Million
depending
on
modifications
required.
Thermo-
Chemical
Hydrolysis
Process
Post-digestion thermo-
chemical hydrolysis uses
low heat, and high Ph
through addition of
KOH/NaOH and high
shear mixing.
▪ Relatively simple
compared to other
Class A processes.
▪ Option for technology
provider to manage
product.
▪ Product is a liquid at 5-8 percent
TS, which would increase hauling
costs.
▪ Drying beds would become
abandoned assets.
▪ No expected reduction of PFAS.
▪ Only one technology provider.
$22 Million
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Class A
Technology General Description Advantages Disadvantages Capital Cost Estimate
Thermal
Drying
Thermal drying typically
uses a fuel such as natural
gas or digester gas to dry
dewatered solids. Various
technology options
including belt, rotary drum,
and paddle dryers.
▪ Reduces hauling costs
by consistently
producing a > 90
percent dry product.
▪ Highly complex process requiring
drying, dust control, air emissions
controls, and dried product
storage.
▪ Drying beds would become
abandoned assets, except if dryer
can be configured to take air dried
solids.
▪ No expected reduction of PFAS.
$64 Million
Thermal
Drying with
Pyrolysis/
Gasification
Dried solids are processed
in either a zero-oxygen
environment (pyrolysis) or
an oxygen-starved
environment (gasification).
Both processes produce
biochar.
▪ Heat produced during
pyrolysis/gasification
is typically used to run
the dryer, reducing the
fuel needed to run the
process.
▪ Promising for
reduction of PFAS,
although not yet
proven.
▪ Highly complex process requiring
drying, dust control, air emissions
controls, pyrolysis/gasification
reactor, and biochar storage.
▪ Drying beds would become
abandoned assets, except if the
process can be configured to take
air dried solids.
▪ Technologies are not well-
established for processing
biosolids; limited operational
experience.
▪ Market for biochar is not well-
established.
$104 Million
Composting Biosolids and bulking
agents (agricultural, yard,
or wood waste) are
ground, combined into
piles for composting and
curing, and then screened.
Various technology options
including windrow, aerated
static pile, and in-vessel
composting.
▪ Market for compost is
well-established.
▪ Relatively simple
process.
▪ Potential reduction of
PFAS through dilution
with bulking agent.
▪ Requires large footprint.
▪ Requires addition of bulking agent
to provide porosity and nitrogen to
the compost mix.
$16 Million
Notes:
(1) Cost estimates were roughly estimated based on Carollo’s biosolids master planning and digestion upgrades estimating experience.
While a full operations and maintenance (O&M) and life-cycle cost analysis was not included in the scope of this evaluation, future costs for hauling and land application were estimated to determine if the potential savings over 20 years could justify the capital costs of the Class A alternatives shown in Table 2.
Note that this analysis assumes a best-case scenario where the new Class A process would not increase the O&M costs, and costs for end-use of the Class A product are assumed to be zero. If the potential end- use cost savings over 20 years are higher than the capital cost estimates, a more detailed evaluation of Class A options would be warranted.
Future costs for hauling and land application of air-dried solids were estimated based on a realistic rate increase scenario of 3 percent increase per year and a worst-case scenario of 10 percent increase per year.
The results of this analysis are presented in Table 3.
TECHNICAL MEMORANDUM 3 – ENVIRONMENTAL OPPORTUNITIES
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Table 3 Projected Future Air-Dried Solids Hauling and Land Application Costs for Realistic and Worst-Case Scenario Realistic Scenario Worst-Case Scenario
Annual hauling and land application rate increase (%) 3 10 Hauling and land application rates ($/WT)(1) $74/WT in 2023 to $130/WT by 2042
$79/WT in 2023 to
$484/WT by 2042
Air-dried solids quantities (WT/year)(2) 2,530 WT in 2023 increasing to 4,120 WT by 2042 Annual hauling and land application costs ($/year) $188,000 in 2023 to $536,000 by 2042
$201,000 in 2023 to
$2.0M by 2042
Present value of hauling and land application costs (2023 $) (3) $4.9M over 20 years $11M over 20 years Notes:
(1) Hauling and land application rates projected from a 2022 rate of $72/WT. (2) Air dried solids quantities were projected proportional to the projected increase in influent BOD loads. (3) Present value calculated assuming an interest/discount rate of 3 percent .
Comparing the potential savings in end-use costs of $4.9M to $11M over 20 years to the capital cost estimates presented in Table 3, it may be worth further evaluating THP, batch TPAD, and composting as potential future Class A alternatives. THP and batch TPAD could potentially also provide alternatives to anaerobic digestion capacity expansion that may be more cost-effective than the baseline mesophilic digestion expansion estimate of $42M. Thermo-chemical hydrolysis is not recommended since it produces a liquid product which would increase product quantities and their corresponding end-use costs and the drying beds would become abandoned assets.
The capital costs for thermal drying, pyrolysis, and gasification are too high to justify further evaluation.
Furthermore, these thermal processes have high O&M costs, so the actual potential savings would be less than the $4.9M to $11M estimated in Table 3, even for this best-case scenario analysis where the Class A product hauling and end-use costs are assumed to be zero. The only future scenario where these processes may be justified is if future PFAS regulations require PFAS removal from biosolids.
3.3.6 Recommendations
Before investing in expansion of the existing mesophilic anaerobic digestion system, with an estimated capital cost of $42M, the City should consider conducting a biosolids master plan (BMP) to comprehensively evaluate options for solids treatment and biosolids product management. The BMP should include, at least, the following evaluations:
▪ After completion of the digestion capacity expansion project (see TM 4 – Near-Term Project Descriptions) and for any future digestion capacity expansion needs, the City could evaluate potentially less expensive ways of increasing digestion capacity such as optimizing thickening, evaluating thickening alternatives, evaluating recuperative thickening, or adding a THP system or batch TPAD system. THP and batch TPAD, which would provide multiple benefits, as they both expand digestion capacity and produce a Class A product.
▪ Evaluation of modifications required for batch TPAD, which, depending on the site -specific required digester modifications, may be the least expensive Class A option. ▪ Evaluation of options for treating PFAS in biosolids, such as pyrolysis and gasification, in case stringent limits get implemented in the future. This evaluation should investigate whether air dried biosolids can be used as a feedstock for pyrolysis/gasification, which would reduce the overall cost of the system.
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▪ Further testing of the City’s air dried biosolids to determine if it is viable to meet Class A through pathogen testing and an evaluation of the regulatory requirements to obtain Class A designation . ▪ Market analysis of various biosolids products to determine other end-use options that do not require hauling to adjacent counties.
▪ Evaluation of potential regional partnerships with nearby wastewater agencies or with nearby composting facilities.
3.4 Energy Opportunities
3.4.1 Introduction
The City is interested in investigating alternative digester gas utilization and energy generation opportunities due to permitting issues with their existing cogeneration system.
3.4.2 Current Digester Gas Utilization and Energy Generation Systems The WRF produces digester gas from anaerobic digestion of primary solids and thickened waste activated sludge. From January 2018 to June 2023, the digesters produced an average of 203,400 standard cubic feet per day (scfd) or about 141 standard cubic feet per minute (scfm) of digester gas. With a 71 percent increase in influent BOD loads projected through 2044, the 2044 digester gas production is estimated to be approximately 240 scfm.
The digester gas is currently conditioned for hydrogen sulfide (H2S) removal and flared. The digester gas is not used in the boilers because they are not permitted to operate using digester gas; instead, natural gas is used to run the boilers.
A gas conditioning and cogeneration system using engine generators was installed in 2017 but has not been used to date due to issues with obtaining an air permit. The gas conditioning system, provided by Unison, has a capacity of 350 scfm and consists of H2S removal vessels containing proprietary media, moisture removal using compression, cooling, and reheating of the gas, and siloxane removal using two sets of lead/lag vessels containing activated carbon. The cogeneration system consists of one 988 kilowatt (Kw) Cummins engine generator (model C1000N6C), equivalent to an annual generation capacity of 8,650,000 kilowatt-hours per year (kWh/year). This engine has an electrical efficiency of 41 percent at 100 percent load. The cogeneration system is equipped with a fuel blending skid which allows for supplementing the engine with natural gas.
In addition, the City has a solar system with a 1 MW generation capacity, installed in 2017..
3.4.3 Regulatory and Financial Drivers
There are several financial incentives for monetizing renewable natural gas (RNG) or electricity produced from renewable sources like digester gas.
For RNG projects, there are number of opportunities to monetize this resource, including:
▪ Renewable Fuel Standard (RFS) Program. The RFS program is managed by the USEPA and used to offset carbon emissions in the transportation sector. The program requires oil and gas producers to purchase specified amounts of fuel credits each year to increase the amount of renewable fuel used.
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The RFS program tracks the production and sale of renewable fuel used as transportation fuel using what is known as a Renewable Identification Number (RIN) or RIN credit. ▪ Low Carbon Fuel Standard (LCFS) Program. The LCFS program is managed at the state or regional level and establishes compliance goals to reduce carbon emissions. The credits available from this program are known as LCFS credits.
▪ Voluntary Markets. These local and regional programs are implemented by corporations or regional natural gas utilities that are focused on sustainability. In some cases, the corporations or utilities may have compliance goals to achieve long-term sustainability goals for RNG.
There are also several financial incentives available for electricity generation from digester gas. For facilities like the WRF which produce less power than they use, the financial incentives available include:
▪ Self-Generation Incentive Program (SGIP): The California Public Utilities Commission’s (CPUC) Self- Generation Incentive Program (SGIP) provides incentives to support existing, new, and emerging distributed energy resources. The incentive for internal combustion engines is $2.00 per watt (W) and the biogas adder is $0.60/W, for a total of $2.60/W. To obtain an SGIP grant, the City must operate the engine on digester gas only, without any natural gas supplementation. The first 50 percent of the grant is paid out after completion of the installation. The remaining 50 percent of the grant is performance based; the electrical generation is metered and reported to the electric utility by an independent third party.
▪ Renewable Electric Renewable Identification Numbers (eRIN): In 2023, the USEPA proposed the addition of eRINs to their RFS program. However, while eRIN generation is set to begin on January 1, 2024, the USEPA has issued a solicitation for feedback and the eRIN program has not yet been finalized.
In addition, the Inflation Reduction Act (IRA), described below, provides funding opportunities for both cogeneration and RNG digester gas projects, as well as solar power and other renewable energy generation projects:
▪ Inflation Reduction Act (IRA): The IRA, passed in 2022, provides funding opportunities for various types of digester gas utilization projects. In addition to a tax credit, available only for private for-profit companies, the program also provides a direct pay option so that non-profits and public agencies can also benefit. A major limitation of this program is that only facilities that begin cons truction before 12/31/2024 are eligible.
In contrast to incentives to digester gas use, some regulations may disincentivize the use of digester gas derived compressed to renewable compressed natural gas (R-CNG) as a vehicle fuel in California. In April 2023, California adopted the Advanced Clean Fleets (ACF) rule that requires a phased transition towards zero-emission medium- and heavy-duty vehicles. As a part of the Advanced Clean Fleets rule, fleet owners operating private services, federal fleets, and state and local government fleets are requi red to transition towards zero emission vehicles (ZEVs). Existing vehicles are allowed to continue operation throughout their useful life. The Advanced Clean Fleet regulations propose the following requirements for public agencies:
▪ By 2024, state and local government fleets, including city, county, special district, and State agency fleets are required to ensure 50 percent of new vehicle purchases are zero-emission. ▪ By 2027, state and local government fleets, including city, county, special district, and State agency fleets are required to ensure 100 percent of new vehicle purchases are zero-emission.
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The ACF rule does not count R-CNG vehicles as ZEVs and is thus expected to reduce the future demand for R-CNG in California. Several agencies including the California Association of Sanitation Agencies (CASA) have been advocating to include R-CNG vehicles as a viable renewable fuel option in the ACF.
3.4.4 Energy Opportunities and High-Level Cost Estimates Digester gas, containing approximately 60 percent methane, is a valuable renewable energy resource that can be used for digester heating, in cogeneration or combined heat and power (CHP) systems, upgraded to renewable natural gas (RNG) for pipeline injection, or upgraded and compresse d to renewable compressed natural gas (R-CNG) for vehicle fueling, as shown in Figure 3 and described below.
Figure 2 Digester Gas Utilization Options
The WRF currently flares 100 percent of its digester gas. The boilers are currently not permitted to utilize digester gas, and instead are fueled with natural gas. The WRF also has a gas conditioning and cogeneration system, which is currently not in use due to permitting issues. Cogeneration systems require gas conditioning to remove H2S, moisture, and siloxanes from the digester gas. Cogeneration systems include heat recovery for digester heating and other heating needs and emissions controls. The heat recovered is typically more than enough to heat mesophilic anaerobic digesters. Cogeneration systems can use microturbines, engine generators, gas turbines, or fuel cells. These options are described in more detail below:
▪ Engine Generators: Engine generators are the most commonly used system in wastewater treatment plants (WWTPs) due to their capacity ranges being suitable for the digester gas quantities typically produced at most WWTPs and their high electrical efficiency. Engine generators of the scale used at
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municipal WWTPs typically range in efficiency from 35 to 42 percent. These units are available from several well-established manufacturers including GE Jenbacher, Caterpillar, and Cummins. ▪ Microturbines: Microturbines are typically only recommended for smaller WWTPs or for WWTPs that need heat recovery in the form of steam. Microturbines come in small modular units and are easier to install and operate, relative to engine generators. However, their electrical efficiency is lower, ranging from 25 to 33 percent. There are only two microturbine suppliers: Capstone and FlexEnergy. ▪ Gas Turbines: Gas turbines are typically recommended for larger WWTPs with potential generation capacities over 4 megawatts (MW).
▪ Fuel Cells: Relative to the other cogeneration technologies, fuel cells are more expensive in both capital and O&M costs. Several WWTPs that operated fuel cells running on digester gas have had operational issues, and the operations at several of these facilities have been discontinued. However, fuel cells have the advantage of having extremely low air emissions relative to the other cog eneration technologies.
Other options the City could consider for digester gas utilization are upgrading the digester gas to RNG for pipeline injection and upgrading and compressing the digester gas to produce R -CNG for vehicle fueling, described in more detail below.
▪ RNG to Pipeline Injection: There are several upgrading technologies including membrane separation, pressure swing adsorption, amine scrubbing, and water scrubbing. Membrane separation is the most commonly used upgrading technology at smaller WWTPs. In these systems, the digester gas is first conditioned to remove H2S, moisture, and siloxanes, before going through the digester gas upgrading system to remove the carbon dioxide and produce a >99 percent methane gas. The systems produce an off-gas containing mostly carbon dioxide with a small amount of methane. This off -gas should be flared or burned in a thermal oxidizer to reduce emissions of methane, a potent greenhouse gas.
Typically, these systems are designed to use the full digester gas stream to maximize the environmental credits available (RIN and LCFS), and natural gas is used to fuel the boilers for digester heating. The viability of pipeline injection depends on the distance to the pipeline injection location and the injection pressure required. The City could contact SoCalGas for further information on the nearest potential injection point and its pressure.
▪ R-CNG to Vehicle Fuel: The required equipment is similar to the upgrading equipment needed to produce RNG for pipeline injection, although the quality requirements for use of R -CNG in vehicles is less stringent. Similar to RNG systems, these systems are typically designed to up grade the full digester gas stream, with natural gas used to fuel the boilers. The viability of this alternative depends on there being sufficient local demand for the R-CNG in CNG vehicles and the proximity of a CNG fueling station. As described in the section above, the demand for R-CNG in California may disappear due to the Advanced Clean Fleet rule which requires full conversion to ZEVs.
Carollo recently estimated Class 5 capital costs (with an expected accuracy range of -30 to +50 percent), O&M costs, and payback periods for digester gas utilization alternatives for two agencies with similar digester gas quantities. These costs are provided below to give the City a rough estimate of what a new digester gas utilization system may cost. However, it is important to note that factors such as digester gas quantity and quality, electricity prices and rate structures, proximity to a suitable pipeline injection location, and design requirements and preferences vary for each specific wastewater agency. ▪ A December 2022 evaluation for the City of Ventura included evaluation of cogeneration using engine generators or microturbines for a design year (2041) average digester gas production of 133 scfm. The TECHNICAL MEMORANDUM 3 – ENVIRONMENTAL OPPORTUNITIES
FEBRUARY 2024 / FINAL / CAROLLO
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WATER RECLAMATION FACILITY - FACILITY PLAN 3-11
capital costs were almost identical for engine generators and microturbines at approximately $11.5 M.
The net savings (calculated accounting for the O&M costs and the power savings) were higher for the engine generator alternative due to the unit’s higher electrical efficiency. The payback period for all options was longer than 20 years.
▪ A February 2021 evaluation for the City of Turlock included evaluation of cogeneration using engine generators, digester gas upgrading for pipeline injection, and digester gas upgrading for vehicle fueling for a design year (2045) average digester gas production of 315 scfm. The vehicle fuel alternative was eliminated due to insufficient local demand for CNG. Even though several City vehicles and trash trucks owned by a solid waste company located adjacent to the treatment plant use CNG, it was estimated that these vehicles could only use about 50 percent of the City’s potential R-CNG production. The capital costs were approximately $13M for the cogeneration alternative and $11M for the pipeline injection alternative. The pipeline injection alternative was favorable due to a suitable PG&E injection location adjacent to the treatment plant. The payback period for the cogeneration alternative was estimated at 15 to 20 years, depending on whether or not a grant of $3 -M could be obtained through the SGIP program. The payback period for the pipeline injection alternative was estimated at 9 to 17 years, depending on the value of the RIN credits that could be obtained.
3.4.5 Recommendations
The WRF already has a digester gas conditioning and cogeneration system. Given this, the least costly energy opportunity is to resolve the permitting issue that is keeping the existing system from operating.
In addition, the City is currently purchasing natural gas to run the boilers because they are not currently permitted to operate using digester gas, resulting in 100 percent of the digester gas being flared.
Resolving this permitting issue should be the first priority. If these permitting issues cannot be resolved, the City should consider either performing a digester gas use study or a more comprehensive energy master plan.
A digester gas use study would focus on evaluating the best use of digester gas, given the current regulatory and financial market. This study should evaluate options including cogeneration using engine generators and digester gas upgrading to RNG for pipeline injection. Given the exclusion of R -CNG vehicles from the Advanced Clean Fleet Rule, the demand for R-CNG is expected to dramatically decrease, so this option is not recommended. However, generation of electricity to fuel electric vehicles shoul d be considered, particularly depending on the incentives that may be provided by the eRIN program, when it is finalized.
An energy master plan would comprehensively evaluate energy saving and energy generation opportunities for the WRF, as well as energy resiliency and greenhouse gas reduction opportunities.
Energy savings could include evaluations of operational optimizations and alternative treatment processes. Energy generation and resiliency opportunities could include additional solar power generation, battery storage, increasing digester gas production through co-digestion of fats, oils, and grease (FOG) and/or food waste, and an evaluation of digester gas use alternatives.
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 4
Near-Term Project Descriptions
FINAL / February 2024
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 4
Near-Term Project Descriptions
FINAL / February 2024
This document is released for the purpose of information exchange review and planning only under the authority of Kyle T. Leonard, February 2024, CA PE 86011.
TECHNICAL MEMORANDUM 4 – NEAR-TERM PROJECT DESCRIPTIONS FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN i
Contents
TM 4 NEAR-TERM PROJECT DESCRIPTIONS 4-1
4.1 Introduction 4-1
4.2 Thickened Waste Activated Sludge Pump Replacements 4-2
4.2.1 Background 4-2
4.2.2 Basis of Design 4-3
4.2.3 Recommendations 4-3
4.3 Dewatering Capacity Expansion 4-3
4.3.1 Background 4-3
4.3.2 Basis of Design 4-3
4.3.3 Recommendations 4-4
4.4 Anaerobic Digestion Capacity Expansion 4-4
4.4.1 Background 4-4
4.4.2 Basis of Design 4-5
4.4.3 Recommendations 4-5
4.5 UV Disinfection System Capacity Expansion 4-6
4.5.1 Background 4-6
4.5.2 Basis of Design 4-6
4.5.3 Recommendations 4-6
Tables
Table 1 Current and Future TWAS Production 4-3
Table 2 Design Capacities for the New Digester 4-6
Figures
Figure 1 Site Layout of Recommended Projects 4-2
Figure 2 Projected Anaerobic Digestion Hydraulic Retention Time 4-5
TECHNICAL MEMORANDUM 4 – NEAR-TERM PROJECT DESCRIPTIONS FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN ii
Abbreviations
ADMM average day maximum month
cu ft cubic feet
GBT gravity belt thickener
gpm gallons per minute
HRT hydraulic retention time
MCC motor control center
PLC programmable logic controller
PS primary sludge
TM technical memorandum
TS total solids
TWAS thickened waste activated sludge
UVT ultraviolet transmittance
VFD variable frequency drive
WRF Water Reclamation Facility
TECHNICAL MEMORANDUM 4 – NEAR-TERM PROJECT DESCRIPTIONS FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 4-1
TM 4 NEAR-TERM PROJECT DESCRIPTIONS
4.1 Introduction
This technical memorandum (TM) summarizes projects that are recommended for implementation within the next six years based on the capacity analysis summarized in TM 1 – Near-Term Process Performance Evaluation. These near-term projects are required to reliably treat current and 6-year projected flows and loads. This TM is not a comprehensive overview of all near-term projects that are required at Visalia’s Water Reclamation Facility (WRF). Certain WRF improvements, such as replacement and rehabilitation improvements, will be needed for aging infrastructure and are discussed at a high level in TM 2 - Condition Assessment. Other WRF improvements for environmental opportunities are discussed at a high level in TM 3 – Environmental Project Opportunities.
The near-term projects are:
▪ Thickened Waste Activated Sludge Pump Replacements.
▪ Dewatering Capacity Expansion.
▪ Anaerobic Digestion Capacity Expansion.
▪ Ultraviolet (UV) Disinfection System Capacity Expansion.
Near-term projects can be seen on the site plan shown in Figure 1. For each project, this TM summarizes the project background and drivers, basis of design, and recommended improvements. Project costs for the recommended projects are summarized in TM 5 – Near-Term Capital Improvement Program.
TECHNICAL MEMORANDUM 4 – NEAR-TERM PROJECT DESCRIPTIONS FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 4-2
Figure 1 Site Layout of Recommended Projects
4.2 Thickened Waste Activated Sludge Pump Replacements
4.2.1 Background
The WRF uses gravity belt thickeners (GBTs) to thicken waste activated sludge. These GBTs were designed to produce thickened waste activated sludge (TWAS) with 5 percent total solids (TS). However, the plant has run into issues with the TWAS pumps tripping from too high of pressure when the TWAS is thickened to 5 percent TS. Therefore, the GBTs are operated to produce TWAS with about 2.5 percent TS, resulting in a significantly higher amount of sludge being sent to the plant’s digesters. Since the capacity of the digesters is currently limited by the hydraulic retention time and not the solids loading rate, this additional volume of sludge being sent to the digesters directly reduces the overall digestion capacity.
Replacing the TWAS pumps with new pumps that can accommodate higher pressures would allow the GBTs to be operated as originally designed and produce TWAS with 5 percent TS. Sending less TWAS to the digesters would restore some additional digestion capacity for accommodating additional increases in flows and loads, resulting in delaying the need for an additional digester and providing more time for the design and construction of the new digester.
TECHNICAL MEMORANDUM 4 – NEAR-TERM PROJECT DESCRIPTIONS FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 4-3
4.2.2 Basis of Design
To determine the future TWAS flows for sizing the new TWAS pumps, sludge flows and loads were developed for current and future conditions using a BioWin model, which is described in more detail in TM 1 – Near-Term Process Performance Evaluation. These current and projected TWAS flows are summarized below in Table 1 and were used as the basis for sizing the new TWAS pumps.
Table 1 Current and Future TWAS Production
Sludge Thickness, percent 2023, ADMM (gpm) 2044, ADMM (gpm) 5 42 61
Abbreviations: gpm - gallons per minute. ADMM - average day maximum month.
4.2.3 Recommendations
It is recommended that these TWAS Pump Replacements improvements be implemented as soon as possible to restore some digestion capacity. Therefore, this project should be on an expedited design and construction schedule. The TWAS Pump Replacements improvements would include the following:
▪ Two higher pressure TWAS pumps.
▪ Replacement of the exposed TWAS piping, valves, and appurtenances in the room. ▪ Retrofitting new variable frequency drive (VFD) buckets into the existing motor control center (MCC) section.
▪ Replacement of local control stations, cable, exposed conduits, conduit supports, and hardware associated with the TWAS pumps.
▪ Replacement of associated instruments, supports, hardware and wire. ▪ Replacement of communication cable between the VFD and programmable logic controller (PLC).
4.3 Dewatering Capacity Expansion
4.3.1 Background
Currently, the City’s WRF has two existing screw presses that were designed to operate as one duty and one standby unit. As previously stated in TM 1 – Near-Term Process Performance Evaluation, the dewatering system does not have sufficient firm capacity, meaning a unit is out of service, for the current flows and loads. Therefore, when flows and loads are high, the plant must operate both screw presses to dewater all of the sludge. Operating both units does not allow plant staff to take a unit out of service, so additional dewatering capacity is required to provide critical redundancy to improve operations of the dewatering process.
4.3.2 Basis of Design
As mentioned above, the WRF does not have sufficient firm capacity for the dewatering system. This project would include the addition of a third screw press to provide additional dewatering capacity to allow the plant to operate two screw presses with a third on standby, providing the necessary redundancy required.
TECHNICAL MEMORANDUM 4 – NEAR-TERM PROJECT DESCRIPTIONS FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 4-4
4.3.3 Recommendations
It is recommended to add a third screw press with the same capacity as the existing screw presses and be implemented as soon as possible to provide redundancy for the dewatering system. Like the TWAS pump replacements, this project should also be on an expedited design and construction schedule. The existing dewatering system was designed with space allocated for an additional screw press on the west side of the existing screw presses. It is recommended that the new screw press be installed in the reserved future space.
According to the future digested sludge flow projections, the existing dewatering feed pump station has sufficient firm capacity so additional dewatering feed pumps are not needed. The dewatered cake conveyors also have sufficient capacity and do not need to be replaced. The existing polymer storage tanks will provide about 30 days of storage at the projected 2030 sludge flows, so additional polymer storage was not included with this project either.
The Dewatering Capacity Expansion improvements would include the following:
▪ One new screw press, flocculation tank, and sludge grinder with the same capacity as the existing units.
▪ New concrete base slab and support columns for the screw press. ▪ Expansion of the elevated platform for the new screw press. ▪ Necessary piping, valves, and appurtenances for the new screw press. ▪ The new screw press would be powered from the existing MCC-DW and use an existing spare breaker that is dedicated for Dewatering Screw Press No. 3.
▪ A new vendor control panel would be installed in the field, and a new cable will be routed through the existing conduit.
4.4 Anaerobic Digestion Capacity Expansion
4.4.1 Background
As previously stated in TM 1 – Near-Term Process Performance Evaluation, the capacity of the anaerobic digestion system is currently limited by the hydraulic retention time (HRT) criteria. At current sludge flows, the digestion system is below capacity with the largest digester, Digester No. 8, out of service, so another digester is needed now to allow the largest digester to be taken out of service. However, it is estimated to take at a minimum 3 years to design, construct, and have a new digester be placed into service. Therefore, thickening the primary sludge (PS) and TWAS feed to the digesters is critical for delaying the need of a new digester by a few years.
Currently, PS feed is not thickened to its fullest potential. The City indicated that it was difficult to thicken PS concentrations greater than 2.5 percent total solids (TS) even though normal operations should allow the primary clarifiers to thicken up to 3-4 percent TS. This is due to long sludge retention times resulting in septic conditions and biogas production, which can hinder the gravity separation process. However, by optimizing PS wastage rates, the WRF should be able to achieve PS with 3 percent TS while still ensuring septic conditions are not established inside the primary clarifiers.
TECHNICAL MEMORANDUM 4 – NEAR-TERM PROJECT DESCRIPTIONS FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 4-5
The GBTs are currently not fully optimized and thicken WAS to 2.5 percent TS instead of 5 percent TS.
However, 5 percent TS could be achieved by replacing the TWAS pumps, as described above.
4.4.2 Basis of Design
Due to the digestion capacity being limited by the HRT, sludge flow projections to the digesters, assuming 3 percent PS plus scum and 5 percent TWAS, were used to determine the year the capacity of the digesters would be reached with the largest unit out of service. Figure 2 presents the projected HRT of the digestion system for the next 6 years with all units in service and with the largest digester, Digester No. 8, out of service.
With the largest digester out of service, due to maintenance or other reasons, the required HRT is not met. Adding another digester that is the same size as the largest existing digester would provide sufficient digestion capacity for over 10 years.
Figure 2 Projected Anaerobic Digestion Hydraulic Retention Time
4.4.3 Recommendations
It is recommended to add a new digester with the same digestion and sludge storage capacities as Digester No. 8. These design capacities are shown below in Table 2. This new digester would allow the plant to meet the required HRT for Class B biosolids if Digester No. 8 needs to be taken offline and provide necessary redundancy to the digestion system.
TECHNICAL MEMORANDUM 4 – NEAR-TERM PROJECT DESCRIPTIONS FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 4-6
Table 2 Design Capacities for the New Digester
Parameter Value
Operating Volume (excluding cone depth) 259,000 cu ft
Sludge Digestion 185,000 cu ft
Sludge Storage 74,000 cu ft
Abbreviations: cu ft – cubic feet.
The Anaerobic Digestion Capacity Expansion improvements would include the following:
▪ Construction of a new digester.
▪ Digester mixing system, including a mixing pump and associated piping, valves, and appurtenances. ▪ Digester heating system, including a sludge recirculation pump, hot water pump, heat exchanger, and associated piping, valves, and appurtenances.
▪ Digester feed transfer pumps and associated piping, valves, and appurtenances. ▪ Yard piping, including digester feed, digested sludge, hot water return/supply, and digester gas . ▪ New electrical and boiler building, with a new boiler to expand the capacity of the main hot water loop and new MCC to power all of the equipment associated with this project.
4.5 UV Disinfection System Capacity Expansion
4.5.1 Background
The existing UV disinfection system was installed in 2017 with a peak flow firm capacity rating of 28.8 mgd. As stated in TM 1 – Near-Term Process Performance Evaluation, this peak flow capacity is insufficient to meet the projected 2030 PWWF of 30.2 mgd, and the UV system needs to be expanded and brought online by 2027 to have sufficient firm capacity to meet the projected PWWFs. This will create necessary redundancy in the system for projected flows.
4.5.2 Basis of Design
The existing UV system was designed with space allocated for installing four additional modules in the existing channels. Installing these four additional modules will increase the firm capacity of the system from 28.8 mgd to 37.0 mgd and provide sufficient firm capacity for the projected 2030 PWWF.
4.5.3 Recommendations
During preliminary design for the UV system expansion, the design assumptions for sizing the original UV system should be revisited and compared to the historical operational data of the system. For example, the system was designed based on a UV transmittance (UVT) of 65 percent, but recent historical data shows that the UVT is higher than 65 percent. Increasing the design UVT could increase the capacity of the existing system but would also decrease the conservatism of the design. For planning purposes, it was assumed that the UV system would be expanded to meet the projected PWWFs.
The UV Disinfection System Capacity Expansion improvements would include the following:
TECHNICAL MEMORANDUM 4 – NEAR-TERM PROJECT DESCRIPTIONS FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 4-7
▪ Installation of four UV modules and associated vendor provided stepdown transformers and power supply units.
▪ Power the new UV modules from Switchboard (SWBD) SWBD-4000B that has 2 breakers dedicated for the UV power transformers.
▪ Utilize the existing conduits to route cable from SWBD-4000B to the stepdown transformers and from the transformers to the power supply units.
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 5
Near-Term Capital Improvement
Program
FINAL / February 2024
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 5
Near-Term Capital Improvement
Program
FINAL / February 2024
This document is released for the purpose of information exchange review and planning only under the authority of Kyle T. Leonard, February 2024, CA PE 86011.
TECHNICAL MEMORANDUM 5 – NEAR-TERM CAPITAL IMPROVEMENT PROGRAM FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN i
Contents
TM 5 NEAR-TERM CAPITAL IMRPOVEMENT PROGRAM 5-1
5.1 Introduction 5-1
5.2 Key Findings and Recommendations 5-1
5.3 Cost Estimate 5-2
5.3.1 General Cost Assumptions 5-2
5.3.2 Project Capital Costs 5-3
5.4 Project Implementation 5-4
5.4.1 Project Durations 5-4
5.4.2 Implementation Schedule 5-4
Tables
Table 1 Capital Cost Estimating Approach 5-3
Table 2 Total Project Capital Cost for Recommended Project 5-3 Figures
Figure 1 Near-Term Projects CIP Cash Flow 5-2
Figure 2 Near-Term Projects CIP Schedule 5-4
TECHNICAL MEMORANDUM 5 – NEAR-TERM CAPITAL IMPROVEMENT PROGRAM FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN ii
Abbreviations
AACE Association for the Advancement of Cost Engineering Carollo Carollo Engineers
CIP capital improvement program
City City of Visalia
TM technical memorandum
TWAS thickened waste activated sludge
UV ultraviolet
WRF Water Reclamation Facility
TECHNICAL MEMORANDUM 5 – NEAR-TERM CAPITAL IMPROVEMENT PROGRAM FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 5-1
TM 5 NEAR-TERM CAPITAL IMRPOVEMENT PROGRAM
5.1 Introduction
This technical memorandum (TM) presents the near-term capital improvement program (CIP) for Visalia’s (City) Water Reclamation Facility (WRF) and a summary of the associated capital costs. The CIP presents an estimate of the City’s capital expenses over the next six years to address any capacity-related recommended improvements to the WRF.
5.2 Key Findings and Recommendations
The near-term CIP identifies critical near-term capacity related projects required at the WRF over the next six years, which are described in TM 4 – Near-Term Project Descriptions and listed below. ▪ Thickened Waste Activated Sludge (TWAS) Pump Replacements. ▪ Dewatering Capacity Expansion.
▪ Anaerobic Digestion Capacity Expansion.
▪ Ultraviolet (UV) Disinfection System Capacity Expansion.
Figure 1 shows an annual cash flow basis for the CIP based on the assumed implementation date for each project. This cash flow analysis is provided as a preliminary tool to assess impacts on the City’s resources over time.
TECHNICAL MEMORANDUM 5 – NEAR-TERM CAPITAL IMPROVEMENT PROGRAM FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 5-2
Figure 1 Near-Term Projects CIP Cash Flow
5.3 Cost Estimate
5.3.1 General Cost Assumptions
The cost estimates were prepared in accordance with the guidelines of the AACE International (the Association for the Advancement of Cost Engineering, 18R-97) for a Class 5 estimate. The AACE Cost Estimate Classification System includes five total estimate classes. Class 5 estimates are appropriate for planning projects before more definitive information, such as detailed designs, is available. Class 5 estimates are typically prepared for any number of strategic business planning purposes, including, but not limited to, project screening, evaluating resource needs and budgeting, and long -range capital planning as is being performed in this Facility Plan. Class 5 estimates have wide accuracy ranges. Typical accuracy ranges for Class 5 estimates are -20 to -50 percent on the low side, and +30 to +100 percent on the high side. These ranges vary based on the technological complexity of the project, the availability and accuracy of appropriate reference information, and the inclusion of an appropriate contingency determination.
$-
$2,000,000
$4,000,000
$6,000,000
$8,000,000
$10,000,000
$12,000,000
$14,000,000
$16,000,000
$18,000,000
$20,000,000
2024 2025 2026 2027 2028 2029
TWAS Pump Replacements Dewatering Capacity Expansion
Anaerobic Digestion Capacity Expansion UV Disinfection System Capacity Expansion TECHNICAL MEMORANDUM 5 – NEAR-TERM CAPITAL IMPROVEMENT PROGRAM FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 5-3
Construction cost estimates account for both direct and indirect costs. Direct costs include materials, labor, construction equipment required for installation, and subcontractor costs. Indirect costs include contractor general conditions, contractor overhead and profit, sales tax, and an estimating contingency.
Direct construction costs for all improvements were estimated using various references. Where possible, the costs from design estimates or construction bid tabs were used. Other cost sources included reference projects, the R.S. Means price catalog, cost curves, and vendor quotes. Costs used from design estimates, construction bid tabs, or reference projects were adjusted for location using R.S. Means location factors and for inflation using the appropriate ENR CCI. Indirect construction costs were estimate d as a percentage of the direct construction cost based on experience and industry-wide standards.
The total project cost was estimated for each project as the total construction cost plus an additional allowance for overall project costs including engineering, legal, administration, permitting costs, etc. Table 1 summarizes the overall approach for developing capital cost estimates.
Table 1 Capital Cost Estimating Approach
Item Cost Formula
Total Direct Cost = A
Estimating Contingency B = 30 percent of A
Sales Tax (1) C = 8.5 percent of half of A + B
General Conditions (2) D = 10 percent of A + B + C
Contractor Overhead and Profit E = 25 percent of A + B + C + D Total Construction Cost = A + B + C + D + E
Engineering, legal, administrative, and permitting (E.L.A.P) costs for implementing the project
E.L.A.P. = 25 percent of Total Construction Cost
Total Project Capital Cost = Total Construction Cost + E.L.A.P.
Notes:
(1) Sales tax is assumed to be applied to 50 percent of the total direct cost (Item A) with estimating contingency (Item B) . (2) General Conditions accounts for mobilization/demobilization and costs incurred for project management, bonds and insurance, and temporary facilities and utilities.
5.3.2 Project Capital Costs
The total project cost estimates for each project are summarized in Table 2. The estimate is at a planning level and is limited to capital costs and does not include O&M costs.
Table 2 Total Project Capital Cost for Recommended Project Project Cost (1)
TWAS Pump Replacements $675,000
Dewatering Capacity Expansion $5,313,000
Anaerobic Digestion Capacity Expansion $42,938,000
UV Disinfection System Capacity Expansion $1,488,000
Notes:
(1) Total project capital costs are provided as present value based on an ENR CCI number of 15157 corresponding to the 20-City Average Index in September 2023. Costs are escalated to the midpoint of construction with an annual inflation rate of 6 percent. Total project costs TECHNICAL MEMORANDUM 5 – NEAR-TERM CAPITAL IMPROVEMENT PROGRAM FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 5-4
include factors for estimating contingency, sales tax, general conditions, and contractor overhead and profit as well as 25 percent allowance for engineering, legal, administration, and permitting costs.
5.4 Project Implementation
This section discusses the estimated project durations as well as when the projects should be implemented.
5.4.1 Project Durations
Implementation activities for the recommended projects include predesign planning, design, bidding and award, construction, commissioning, and environmental permitting. Project durations were estimated under the following assumptions:
▪ Smaller-sized projects (those less than $1.0M) can be completed in two years or less, with one year for planning, design, and bidding, and one year for construction and startup. ▪ Medium-sized projection (those between $1.0M and $10M) can be completed in two to three years, with one year for planning, design, and bidding, and one to two years for construction and startup. ▪ Larger-sized projects (those greater than $10M) can be completed in three to five years, with one to two years for planning, design, and bidding, and two to three years for construction and startup .
5.4.2 Implementation Schedule
Plant capacity defines not only the need for the projects, but also implementation timing. The implementation timing, determined by when the plant needs additional capacity, and the project duration assign each project a start and completion date. An expedited schedule for design and construction was used for the TWAS pump replacement and dewatering capacity expansion projects. The recommended implementation schedule for the near-term projects can be seen below in Table 2. Project timing and phasing was based on the criticality of the improvements on treatment process reliability.
Figure 2 Near-Term Projects CIP Schedule
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 6
Near-Term Capital Improvement
Program Financing Opportunities
FINAL / February 2024
Water Reclamation Facility - Facility Plan
TECHNICAL MEMORANDUM 6
Near-Term Capital Improvement
Program Financing Opportunities
FINAL / February 2024
This document is released for the purpose of information exchange review and planning only under the authority of Kyle T. Leonard, February 2024, CA PE 86011.
TECHNICAL MEMORANDUM 6 – NEAR-TERM CAPTIAL IMPROVEMENT PROGRAM FINANCING OPPORTUNIES FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN i
Contents
TM 6 NEAR-TERM CAPITAL IMPROVEMENT PROGRAM FINANCING
OPPORTUNITIES 6-1
6.1 Introduction 6-1
6.2 Federal and State Grants and Loans 6-1
6.3 Conclusion 6-10
Tables
Table 1 Federal Funding Programs 6-4
Table 2 Legislative Funding Programs 6-8
Table 3 State Funding Programs 6-8
TECHNICAL MEMORANDUM 6 – NEAR-TERM CAPTIAL IMPROVEMENT PROGRAM FINANCING OPPORTUNIES FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN
Abbreviations
AIS American Iron and Steel
BABA Build America, Buy America
BIL Bipartisan Infrastructure Law
BRIC Building Resilient Infrastructure and Communities
CDS Congressionally Directed Spending
CEQA California Environmental Quality Act
CIP capital improvement program
City City of Visalia
CPF Community Project Funding
CWSRF Clean Water State Revolving Fund
DAC disadvantaged community
DBE Disadvantaged Business Enterprises
DOE Department of Energy
DWR Department of Water Resources
EDA Economic Development Administration
EPA Environmental Protection Agency
FEMA Federal Emergency Management Agency
GO General Obligation
HUD Department of Housing and Urban Development
IBank Infrastructure and Economic Development Bank
IRS Internal Revenue Service
ISRF Infrastructure State Revolving Fund Program
MHI median household income
NEPA National Environmental Policy Act
OPR Office of Planning and Research
PF principal forgiveness
USBR micrograms per liter
RRGP Regional Resilience Grant Program
SCADA supervisory control and data acquisition
SWRCB State Water Resources Control Board
TM technical memorandum
US ACE United States Army Corps of Engineers
USBR United States Bureau of Reclamation
USDA United States Department of Agriculture
WIFIA Water Infrastructure Finance and Innovation Act
WRF Water Reclamation Facility
WRFP Water Recycling Funding Program
TECHNICAL MEMORANDUM 6 – NEAR-TERM CAPTIAL IMPROVEMENT PROGRAM FINANCING OPPORTUNIES FEBRUARY 2024 / FINAL / CAROLLO
CITY OF VISALIA
WATER RECLAMATION FACILITY - FACILITY PLAN 6-1
TM 6 NEAR-TERM CAPITAL IMPROVEMENT PROGRAM
FINANCING OPPORTUNITIES
6.1 Introduction
This technical memorandum (TM) presents a high-level overview of potential funding opportunities for the near-term projects for the City or Visalia’s (City) Water Reclamation Facility (WRF). The City has identified critical near-term projects, which are described in TM 4 – Near-Term Project Descriptions, for its WRF to meet current and projected demands as well as provide treatment redundancy to prevent disruption caused by system failures or maintenance reasons. A search of availabl e federal and state grant and loan opportunities was conducted to identify potential funding mechanisms that can assist the City with project costs.
6.2 Federal and State Grants and Loans
Federal and state funding sources and programs are continuously evolving and influenced by legislative initiatives and regulatory drivers which can impact funding program priorities, program authorizations and appropriations, and project applicability. The $1.2 trillion Infrastructure Investment and Jobs Act, also known as the Bipartisan Infrastructure Law (BIL), has significantly impacted the short -term effects of federal and statewide funding on water-related projects, although long-term impacts of BIL on funding programs is currently unknown.
Federal, state, and local grant and loan funding sources are available for the planning, design , and construction of water, wastewater, and public infrastructure projects. Grants and low interest loan funding programs typically target specific types of projects and/or have specific objectives that a project must achieve. Agencies often require projects to meet as many objectives as possib le, such as:
▪ Builds Regional partnerships.
▪ Incorporates integrated project benefits.
▪ Enhances water conservation or efficiency.
▪ Protects groundwater resources.
▪ Provides renewable energy improvements or energy efficiency. ▪ Addresses risk and resiliency.
▪ Demonstrates consistency with the State and Regional policies and objectives. ▪ Demonstrates regional cooperation and partnerships with partners and stakeholders. ▪ Serves a Disadvantaged Community (DAC) or severely DAC.
Many of the federal and state programs listed do not fund projects driven primarily by growth , which will likely be a limiting factor for a number of programs. However, there are near-term projects not driven by growth and may have an opportunity for partial funding that should be investigated.
Available federal, state, and local funding sources should be considered as potential funding mechanisms to help reduce the overall costs of the projects for the City and its rate payers. However, it is important to TECHNICAL MEMORANDUM 6 – NEAR-TERM CAPTIAL IMPROVEMENT PROGRAM FINANCING OPPORTUNIES FEBRUARY 2024 / FINAL / CAROLLO
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recognize that due to the above-mentioned factors, sources of low interest loan financing and grant funding are limited.
Federal and State funding programs generally providing key opportunities for water and wastewater projects include the United States Environmental Protection Agency (USEPA), the State of California’s Clean Water State Revolving Fund (CWSRF), United States Bureau of Reclamation (USBR), Department of Energy (DOE), United States Army Corps of Engineers (US ACE), United States Department of Agriculture (USDA), Department of Housing and Urban Development (HUD), etc. While EPA’s “Water Infrastructure Finance and Innovation Act [WIFIA] and State of California’s CWSRF programs provide some of the best avenues for securing larger sources of loan funding (and potential principal forgiveness), demand for SRF loans are high. While grant programs have the obvious advantage over loans – they do not require repayment – these programs typically do not fully finance a project and are more competitive to secure and are more specific in program priorities.
There are numerous factors that should be considered in the pursuit of external low interest loan and grant funding, including:
▪ Federal and State funding programs are project specific – requiring a good fit of the project to the program priorities. Most low interest loan and grant programs target a specific type of project or purpose. For a project to be competitive, it needs to meet the intent of the program. ▪ Grant programs typically do not cover the full cost of the project. Most federal and state grant programs do not cover the full cost of the project, requiring the sponsoring agency to provide a minimum cost share ranging from 25 to 75 percent (in-kind donations are applicable matches). ▪ Demonstration of Ability to Pay for Project. Typically funding agencies require the Agency to demonstrate the ability to construct, operate, and maintain the project without external funding. ▪ Funding Restrictions. Limited programs allow for the retroactive funding of design and construction work, and some programs will only fund activities that are conducted post selection for award or even require entering into an agreement prior to starting work activities. Most federal programs do not allow for earth disturbance activities prior to environmental (National Environmental Policy Act [NEPA]) clearance.
▪ Application Timelines. Application timing is critical for most grant and loan programs. » Typically grant programs release funding announcements once each year with a 45 to 60 -day window to apply, and availability varies year to year pending Congressional appropriations. » Low interest loan programs typically accept applications on a rolling basis (e.g., WIFIA, SRF), however may require submission of project concepts by a prescribed date. ▪ Award Timing. With the increased interest in external funding and limited funding agency staff availability, the review, selection, and execution of a funding agreement can take on average 12 months and sometime longer.
In general, agencies should plan on submitting a loan application 6 to 12 months in advance of when funding is needed and definitely prior to construction start. ▪ Project and Documentation Readiness / Readiness to Start Construction. Identification of required project documentation early on is critical in order to ensure the appropriate level of documentation (e.g., engineering, environmental, and financial) is available to support the grant application. ▪ Low Interest Loan and Grant Awards is NOT a promise of grant reimbursement. » Most low interest loans and grants are reimbursements and not cash up front. This requires that a source of funding be available for the construction of the project.
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» Grant reimbursements are subject to annual budget and appropriations processes and thus disbursement of grant funds on schedule is not guaranteed. ▪ Federal Compliance Requirements: Federal funding sources require compliance with federal requirements including American Iron and Steel (AIS), Davis Bacon Wage Determinations, Anti- lobbying, Disadvantaged Business Enterprises, Build America, Buy America (BABA) and reporting requirements. This can add to the overall administrative and construction costs as well as to the administrative requirements for the project.
Because of the constraints of federal and state grant and loan programs, some agencies secure low interest loan financing for the entire project while simultaneously pursuing grants where the entity will be competitive. Smaller grants can also be pursued as they are helpful in building relationships with funding agencies and reducing the financial burden on the City.
Potential federal, legislative, and state funding programs to evaluate further for the City’s projects are summarized in Tables 1, 2, and 3, respectively. In addition to summarizing specific funding program information, the table includes a discussion on applicability of the program to the City’s projects as well as next steps for preparing associated applications.
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Table 1 Federal Funding Programs (1)
Program Agency Type Description Deadlines/Next Steps Priority Water Infrastructure Finance and
Innovation Act (WIFIA)
U.S. Environmental
Protection Agency (EPA) Loan
Low-interest financing mechanism for large dollar value water, wastewater, stormwater, green infrastructure, energy efficiency projects, alternative water supply, aquifer recharge, drought preventing/reduction/mitigation projects or a package of projects serving a similar purpose and secured by a common security thread.
Provides up to 49% of the total project financing; agency is required to provide 51% match (SRF, bonds, cash reserves, other grants, etc.). Maximum loan term is 35 years from substantial completion. (Including 5 -year deferment of start of repayments). Projects must cost no less than $20 million, or $5 million for small community projects (population of 25,000 or fewer). Smaller projects can be grouped to meet minimum project cost limit.
Interest rate is equal to the US Treasury rate of a similar maturity. Funds can be used to cover planning/design (retroactive), and construction activities.
Two step application process: Letter of Interest and application. Prospective borrowers can submit letters of interest for review by EPA on a rolling basis from the date listed in the Notice of Funding Opportunity until the earlier of (i) the commitment of all available funding made available for that round and (ii) publ ication of a subsequent notice cancelling or overriding the current NOFA. A rolling selection process allows EPA to provide year -round access to WIFIA funding and submit quicker selection decisions to prospective borrowers. Application fees apply (average $200,000 - $300,000 pending reviews and legal negotiations).
Most recent NOFO released stated that the FY22 lending capacity was $5.5 billion and that letters of interest would be accepted starting September 6, 2022.
Applications accepted on rolling basis until funding is depleted or new announcement of funding ability is announced.
https://www.epa.gov/wifia
High Priority
Low-interest loan funding with $20
million project minimum.
Public Works and Economic
Adjustment Assistance Programs
Department of Commerce
Economic Development
Administration (EDA)
Grant
Program promotes long-term economic development and assists in the construction of public works and the development of facilities needed to initiate and support the creation or retention of permanent private -sector jobs in areas experiencing long-term economic deterioration and distress. The program provides funding for the construction and/or design of infrastructure to enable them to become more economically competitive. Water and sewer system improvements have been funded historically through this program. Construction projects are expected to range from 12 to 48 months and are expected to be completed within 5 years from the award date.
Eligible projects:
▪ Must be consistent with the region’s current Comprehensive Economic Development Strategy (CEDS) or equivalent EDA-accepted regional economic development strategy. ▪ Lead to the creation or retention of long-term jobs that provide living wages (preferably, not seasonal). ▪ Be located in areas that meet at least one of the following criteria: low per-capita income, unemployment above the national average, or “special need” as determined by EDA.
$121.5 million is available for the Public Works program and $39.5 million for the EAA program . Average grant awards are approximately $3 million with Public Works grants approximately $1.4 million. Average EAA grants are $650,000.
Although not a defined rule, applicants may receive $15,000 per job created. Federal/Nonfederal cost share is 50/50.
Federal requirements apply.
Applications accepted on rolling basis until funding is depleted or new announcement of funding ability is announced.
https://www.grants.gov/web/grants/view-opportunity.html?oppId=346815 Contact Wilfred Marshall at 310-261-6005 or [email protected] Low Priority
Project must provide evidence of job
creation and spur economic growth.
Building Resilient Infrastructure
and Communities (BRIC)
Program
Federal Emergency
Management Agency
(FEMA)
Grant
FEMA pre-disaster hazard mitigation program to incentivize new, innovative, large infrastructure projects that build resilient communities and reduce risks from hazards such as wildfires, drought, hurricanes, earthquakes, extreme heat, and flooding.
Total program funding was $1 billion for FY 2023 with a $50 million cap per project. Project must be included in a FEMA-approved Hazard Mitigation Plan, and the project must comply with 2018 and 2021 International Building Codes. Program requires a cost share of 75% to 25%, federal to non-federal. The program offers an increased cost share, 90% federal share, for economically disadvantaged rural communities as well as 100% management costs for all.
Notice of Interest typically due in summer with full application due approximately three months later.
Contact [email protected] for more information.
https://www.caloes.ca.gov/office-of-the-director/operations/recovery- directorate/hazard-mitigation/bric/
Not applicable to selected capital
improvement program (CIP) projects
but may be of interest to the City.
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Program Agency Type Description Deadlines/Next Steps Priority WaterSMART Water and Energy
Efficiency Grants
U.S. Bureau of Reclamation
(USBR)
Grant
Eligible projects include projects that result in quantifiable and sustained water savings, increase renewable energy use, and improve energy savings, and support broader water quality sustainability benefits. Eligible applicants include public agencies or a private entity service in the capacity of a public agency.
Types of projects include water conservation projects (canal lining, municipal metering, irrigation flow measurement, SCADA, high efficiency applications, landscape irrigation, and others) and renewable energy projects (solar/wind energy and hydropower).
Requires a 50% cost share and federal requirements compliance (NEPA, AIS, BABA, Davis Bacon, etc.) Three funding limits:
▪ $500,000 (typically for projects completed within a year). ▪ Up to $2,000,000 (for projects to be completed in 3 years). ▪ Up to $5,000,000 (for projects to be completed in 3 years).
Applications are due February 22, 2024.
https://www.usbr.gov/watersmart/weeg/
Low Priority
Project does not meet program
priorities/type of projects funded.
WaterSMART Small-Scale Water
Efficiency Projects USBR Grant
Reclamation provides funding to irrigation and water districts, tribes, states and other entities with water or power delivery authority for small water efficiency improvements that are limited in scope.
Eligible projects:
▪ Canal lining/piping.
▪ Municipal metering.
▪ Irrigation flow measurement.
▪ Supervisory control and data acquisition and automation (SCADA). ▪ Landscape Irrigation measures.
▪ High efficiency indoor appliances and fixtures.
▪ Upgrades to commercial cooling systems to improve water use efficiency.
Up to $100k in Reclamation funds for 2-year projects. Maximum total project costs of $225k with a 50% non-federal cost share required.
FY24 funding announcement is accepting applications until January 16, 2024. Expected Award of Funding is in September 2024.
Contact Nickie McCann at 303-445-3733 or [email protected] https://www.usbr.gov/watersmart/swep/index.html
Low Priority
Project does not meet program
priorities/type of projects funded.
WaterSMART Planning and
Project Design Grants USBR Grant
Funding for collaborative planning and design projects to support water management improvements.
Grant categories:
▪ Water Strategy Grants to conduct planning activities that will improve water supplies (e.g., water supplies to disadvantaged communities that do not have reliable access to water, water marketing, water conservation, drought resilience, and ecological resilience).
▪ Project Design Grants to conduct project-specific design for projects to improve water management. ▪ Comprehensive Drought Contingency Plans.
Up to $400,000 per application for projects that can be completed within 3 years. Approximately $35 million is available under this program. Approximately 60-70 projects will be awarded, contingent on appropriations.
Most projects except those for tribes or disadvantaged communities will require a 50 percent cost share. Compliance with federal requirements apply (NEPA, AIS/BABA, Davis Bacon, etc.).
Funding deadline for FY23 is Oct. 17, 2023.
Deadline for FY24 is April 2, 2024.
Contact for Water Strategy Grants: Irene Hoiby Mail Code [email protected] or 303-445-3575
Project Design Grants: Nickie McCann [email protected] or 720-610- Drought Contingency Planning: Sheri Looper [email protected] or 916- 978-5556
Not applicable to selected CIP
projects but may be of interest to
the City.
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Program Agency Type Description Deadlines/Next Steps Priority WaterSMART Drought
Response Program: Drought
Resilience Projects
USBR Grant
USBR will provide funding for projects that increase water supply reliability and build long -term resilience to drought.
To be eligible for funding, the proposed project scope should go beyond routine water management activities or activities required by state law for conservation and efficiency. The proposed project should also help avoid the need for emergency response actions. Approximately 25 to 40 projects will be funded contingent upon available federal appropriations.
Eligible projects
▪ Infrastructure projects that increase the reliability of water supplies. ▪ Groundwater recovery that increases the reliability of water supplies. ▪ Projects that improve water management through decision support tools, modeling, and measurement. ▪ Domestic water supply projects for tribes or disadvantaged communities without reliable water access .
Funding limits:
▪ Up to $500,000 for projects to be completed within two years. ▪ $2 million for projects to be completed within three years. ▪ $5 million for large projects to be completed within three years. ▪ Up to $10 million for domestic water supply projects for tribes or disadvantaged communities.
A 5% non-federal cost-share is required for domestic water supply projects for tribes or disadvantaged communities.
All other projects require a 50% non-federal cost share. Compliance with federal requirements apply (NEPA, AIS/Build America, Buy America, Davis Bacon, etc.).
Funding deadline is Nov. 7, 2023
Contact Interior Region 10: California-Great Basin - Anna Sutton, 916-978- 5214, [email protected]
https://www.usbr.gov/drought/
Not applicable to selected CIP
projects but may be of interest to
the City.
Section 219:
Environmental Infrastructure
U.S. Army Corps of
Engineers (US ACE) Grant
Section 219 authorizes the US ACE to aid non-federal interests (local communities, water districts, sanitation districts, etc.) in carrying out water-related environmental infrastructure and resource protection and development projects; this includes wastewater treatment facility projects. The program has been directed by recent legislation to focus on prioritizing assistance to underserved, economically distressed, and economically disadvantaged minority communities.
Program requires a cost share of 75% to 25% of federal to non-federal funding. The application is a two-step process with Congressional authorization required followed by appropriation of funds.
Discussion with local representatives is required for Congressional approval.
https://www.spl.usace.army.mil/Missions/Civil-Works/Projects-Studies/
Low Priority
City demographics do not fit funding
priorities well. Lengthy funding
process.
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Program Agency Type Description Deadlines/Next Steps Priority Energy Efficiency and
Conservation Block Grant
(EECBG) Program
US Department of Energy
(DOE) Grant/Voucher
This program allows for either grants or vouchers. Vouchers can be used for technical assistance and/or rebates for the purchases and installation of energy efficiency or clean energy equipment. Technical assistance may include, but not limited to, the following:
▪ Energy plan development.
▪ Decarbonization planning and roadmaps.
▪ Identification of best practices.
▪ Building audits.
▪ Renewable energy system design.
▪ Cost effectiveness studies.
Other eligible uses of funds include, but are not limited to, the following:
▪ Developing and implementing energy efficiency and conservation strategy. ▪ Retaining technical consultant services to assist the eligible entity in the development of such a strategy. ▪ Performing energy efficiency retrofits.
▪ Conducting residential and commercial building energy audits. ▪ Establishing financial incentive programs for energy efficiency improvements.
The voucher application is separate from applying for grant funds; voucher applications are streamlined with reduced documentation compared to applying for a federal grant. DOE can process voucher applications at least 30 days quicker than grant applications.
The grant option for this program is a formula grant, which means eligible cities receive a specific allocation of money.
The City of Visalia was allocated $182,320 for the current period. It is recommended to consider pursuing the voucher option if the entity’s allocation is less than $250,000 or if staffing capacity is limited since the voucher approach is streamlined and less burdensome.
Applications are due April 30, 2024.
https://www.energy.gov/scep/energy-efficiency-and-conservation-block- grant-program
Medium Priority
An energy study would qualify for
this program. It is recommended to
monitor this funding opportunity as it
is not always available.
Business Energy
Investment Tax Credit
Internal Revenue Service
(IRS) Tax Rebate
The Inflation Reduction Act of 2022 expanded existing clean energy tax credits so non-taxable entities can take advantage of the savings. ITC is a tax credit that reduces the federal income tax liability for a percentage of the cost of a clean energy system that is installed during the tax year. Tax-exempt organizations may file paperwork with the IRS to receive a direct pay subsidy for projects started before January 1, 2025. Projects that commence construction on or after January 1, 2025, may receive a tax credit under the new Clean Electricity Investment Tax Credit.
Projects under 1 MW are not required to meet the new labor standards established by the Inflation Reduction Act to receive a full 30 percent tax credit. Projects that begin construction after 2021 and before 2025 can receive the full tax credit of 30 percent.
Projects over 1 MW will receive a base tax credit of 6 percent but can receive the 30 percent tax credit if they meet prevailing wage and apprenticeship requirements. Other bonuses given for American iron and steel components.
Eligible projects: Solar, fuel cells, wind turbines, geothermal systems, microturbines, CHP, offshore wind, waste energy recovery, energy storage systems, thermal energy storage systems, qualified biogas property, and microgrid controllers.
https://www.irs.gov/instructions/i3468#en_US_2022_publink1000297066 Not applicable to selected CIP
projects but may be of interest to the
City.
Note:
(1) The following funding programs were evaluated and rejected from consideration due to eligibility requirements and other restrictions: HUD Community Development Block Grant Programs, USDA Rural Development Water and Environmental programs, and U.S. Department of Energy programs.
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Table 2 Legislative Funding Programs
Program Agency Type Description Deadlines/Next Steps Priority Community Project Funding
(CPF)/Congressionally Directed
Spending (CDS)
U.S. Congress Directed
Appropriation
CPF is a mechanism by which members of Congress can request funding for specific projects in their home state that have been submitted for consideration by state and local government entities and nonprofits, also known as “earmarks.” Members of Congress can request direct funding for specific entities and projects in their districts to serve the public good.
Members may request funding for up to 15 projects in their community for FY24, although only a handful may be funded. Projects with demonstrated community support are considered. CPF is limited to no more than 0.5 percent of discretionary spending. The average funding awards range from $3 to $5 million; but can be higher. Projects are ultimately selected by the House of Representatives and the Senate with funding, if approved, distributed as part of the federal appropriations process the next FY (October through September). Funds are to be spent within one (1) year.
Contact Congressman Tom McClintock to discuss the possibility of an earmark. Contact his office at 916-786-5560.
Contact Senator Alex Padilla at
[email protected]
Link:
https://appropriations.house.gov/sites/republicans.appropriations.hous e.gov/files/FY24%20Comunity%20Project%20Funding%20Guidance.p df
High Priority
Table 3 State Funding Programs
Program Agency Type Description Deadlines/Next Steps Priority Infrastructure State Revolving
Fund Program (ISRF)
Infrastructure and Economic
Development Bank (IBank) Loan
IBank's ISRF Loan Fund program provides low-cost, direct loans to local governments and nonprofits sponsored by public agencies for a wide variety of public infrastructure and economic expansion projects (excluding housing) that improve and sustain communities, helping individuals and families thrive. Program focuses on small and mid- /moderate-sized local governments and special districts — including those in underserved regions and communities. ISRF financing is available in amounts ranging from $1 million to $65 million with loan terms for the useful life of the project up to 30 years. No scoring mechanisms. IBank operates on a first-come, first-served basis (no scoring mechanism). No CEQA plus, AIS, BABA, or Federal Requirements; will require Davis Bacon. Most recent published interest rate was 4.36% in January 2023.
Timing: Application accepted year-round with Preliminary Review (4-6 weeks) followed by Credit Risk Committee Meeting, Application and Final Board Meeting (6-7 month process).
Contact: 916-341-6600 or [email protected] Link: https://ibank.ca.gov/
High Priority
Interest rates are not as low as SRF
and WIFIA, but applications are less
complex.
Clean Water State Revolving
Fund (CWSRF)
State Water Resources
Control Board
(SWRCB)
Loan/Grant
The CWSRF program provides low-interest loans to eligible entities for a wide range of wastewater and stormwater projects that protect surface water and groundwater resources.
Program Eligibility (including, but not limited to):
▪ Publicly owned wastewater treatment construction, repair, or replacement. ▪ Implementation of a nonpoint source management plan.
▪ Decentralized systems treating municipal or domestic sewage. ▪ Reducing, treating, or managing stormwater.
▪ Reducing demand to publicly owned works through conservation. ▪ Watershed projects.
▪ Reducing energy consumption.
▪ Projects for reusing or recycling wastewater or stormwater. ▪ Increasing security at publicly owned treatment works.
Loan rate is 1/2 of the most recent State General Obligation (GO) Bond Rate at the time of approval. Terms are available for up to 30 years. Principal forgiveness (PF) may be available to disadvantaged borrowers or borrowers that incorporate sustainability into projects. PF is also available for public health projects, estuary projects, water recycling, and stormwater projects. PF Funding for septic-to-sewer conversions for small, disadvantaged communities is available at up to $125,000 per household.
Project will be scored and prioritized based in part on project’s readiness to being construction. If plans are greater than 49% complete on December 31, then the project will receive 1 “construction readiness point.” If greater than 89% complete on December 31, then 2 points are given. If plans are less than 50%, no points are given.
Applications accepted year-round via portal (FAAST), email and hard copy.
[email protected] or (916) 327-9978
https://www.waterboards.ca.gov/water_issues/programs/grants_loans/ srf/
Low Priority
CWSRF program is over committed
currently, and priority is given to small,
disadvantaged communities.
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Program Agency Type Description Deadlines/Next Steps Priority Water Recycling Funding
Program (WRFP) – Planning and
Construction Grants
SWRCB Loan/Grant
The WRFP funds the planning and construction of recycled water treatment facilities, storage facilities, pumping facilities, groundwater recharge facilities, and distribution systems, including onsite improvements. The end use of recycled water must benefit the community as a whole and offset potable water usage. Onsite recycled water application is not eligible. For non-DACS/SDACs, agencies must apply through the CWSRF program and be on the fundable list to be eligible for funding. For 203-2024 funding, projects need to apply for the fundable list by December 31, 2023.
The program required a 50/50 cost share. Historically under Prop 1 of the 5 0% of funding from the WCPP, up to 35% can be in grant form used for construction costs, while the remaining portion would be a loan, which could be used for both construction and soft costs. For non-DACs and DACs, grant funding is capped at $5 million. SDACs may receive more funding with the deputy director’s approval. Through the Governor’s Budget, $160 million is being allocated over three years (2021-2023) for recycled water projects and groundwater projects each, so funding will hopefully follow a similar formula to when Prop 1 was being implemented.
With State funding, federal cross cutters do not apply including BABA, Disadvantaged Business Enterprises (DBE), Davis Bacon, and AIS to name a few. Furthermore, only need California Environmental Quality Act (CEQA) documentation.
Sandeep Kals
916-324-8404
[email protected]
Not applicable to selected CIP projects
but may be of interest to the City.
Regional Resilience Grant
Program (RRGP)
Governor’s Office of Planning
and Research (OPR) Grant
New grant program that funds planning and implementation projects that strengthen climate change resilience at a regional scale. The RRGP funds projects led by partnerships that involve multiple jurisdictions working together to address the most significant climate change risks in their regions, especially in communities that are most vulnerable to climate change impacts. These impacts could include wildfires, rising sea levels, droughts, floods, increasing temperatures, and extreme heat events.
Up to $50 million is available. The funding range for planning projects is $150,000 to $650,000. The funding range for implementation projects is $650,000 to $3,000,000. Cities must work collaboratively with at least one community-based organization to apply.
An Intent to Apply Survey is required.
Contact [email protected].
https://opr.ca.gov/climate/icarp/grants/regional-resilience-grant.html Not applicable to selected CIP projects
but may be of interest to the City.
Urban Community Drought Relief
Program
Department of Water
Resources (DWR) Grant
Under the Budget Act of 2021, approximately $285 million in drought relief funding was made available for interim and immediate drought relief to urban communities. Approximately $175 million will be available in the current funding cycle. A set-aside of at least $85 million will be made to support underrepresented communities and Native American Tribes (Tribes).
Eligible planning, engineering and construction project types include hauled water, installation of temporary community water tanks, bottled water, water vending machines, emergency water interties, new wells or rehabilitation of existing wells, construction, or installation of permanent connection to adjacent water systems, recycled water projects that support immediate relief to potable water supplies, fish and wildlife rescue, protection, and relocation, and drought resiliency planning. Project must be included in an Urban Water Management Plan.
There is a minimum award amount of $3 million per applicant. Smaller projects may be bundled together in a single application to meet the minimum grant award requirement. Applicants are required to have 25% non -state funding match; however, underrepresented and tribal applicants are exempt from this requirement. Funding limits have not yet been determined.
Program is no longer open.
Contact: [email protected]
Link: https://water.ca.gov/Water-Basics/Drought/Drought- Funding/Urban-Drought-Grant
Not available at this time.
Program is no longer accepting new
applications but may reopen at a later
date. Program should be monitored.
Community Development Block
Grant (CDBG)
U.S. Department of Housing
and Urban Development
(HUD)/City
Grant
HUD-awarded funds for local projects. Available to local governments, counties and municipalities. Eligible to fund community water and wastewater projects.
CDBG funds are provided as grants to non-entitlement jurisdictions. Grants can vary based on annual allocations and activity limits. Must address one of three national objectives:
▪ Benefit to low- and moderate-income persons
▪ Aid in the prevention or elimination of slums and blight, or ▪ To meet an urgent need
Internal City discussion would be necessary to use fixed CDBG funding for wastewater projects.
https://www.visalia.city/depts/community_development/housing_n_cdb g_services/community_development_block_grant/default.asp Low Priority
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6.3 Conclusion
This TM summarizes current federal and state grants and low-interest loans that are potential sources of financing for the City’s WRF near-term projects. These programs are competitive and limited in their funding capacity, with program funding availability dependent upon annual appropriations, along with other restrictions.
Many of the federal and state programs listed do not fund projects driven primarily by growth. The City’s near-term projects have several beneficial characteristics that could be further investigated to see if the project could be eligible for funding. The City is a small community not included in one of the state’s Active Management Areas. According to current U.S. Census reporting, the area has a Median Household Income (MHI) of $69,252, approximately 82 percent of California’s average MHI. Even though this is over California’s 80 percent definition of a DAC, it would be prudent to talk with agencies to understand what U.S. Census data is being used and if the City might be considered a DAC. By being classified as a DAC, the City could be eligible for lower interest rates and principal forgiveness.
It should be noted that projects funded with federal financing would need to comply with NEPA, AIS, BABA, Davis Bacon, DBE, competitive procurement, etc. These conditions may add to the project’s overall cost, influence project schedules, and increase some administrative burden.
Critical to the success of securing external funding is the tracking of potential funding opportunities, fit of the project to the funding program priorities, readiness of the project, and timing of application submittals. Because many programs have limits on the amount of funding they can offer, it is important to apply early and with complete documentation to prevent complications in the funding process.
The City’s community demographics put it at odds with some federal programs’ focus on funding projects in small, rural and/or disadvantaged communities. Despite this restriction, there are several opportunities available at the federal and state level that should be further evaluated for financing the project.
The following funding opportunities may provide for low interest loan or grant opportunities for the projects listed in the City’s Near-Term CIP:
▪ U. S. Environmental Protection Agency – WIFIA (low interest financing). ▪ Department of Energy – EECBG Program (grant or voucher program). ▪ State of California - CPF/ CDS (directed appropriations via Congress). ▪ State of California – ISRF (loan program).
▪ State of California – CWSRF (low interest financing with eligible principal forgiveness for disadvantaged communities and green projects).